Agrochemical gel compositions

ABSTRACT

Improved aqueous herbicidal compositions comprising at least one water-soluble herbicide and a gel forming agent are provided. The compositions are generally characterized as pseudoplastic, elastic and having a relatively high stationary viscosity. The compositions provide enhanced foliar retention and resistance to drying thereby allowing for improved uptake of the herbicide into the plants and/or translocation within the plant in order to more effectively kill the plants at reduced application rates in kilograms of herbicide per hectare, even in the absence of a surfactant. Methods for confined application of the compositions of the invention to control the growth of unwanted plants are also provided.

FIELD OF THE INVENTION

The present invention generally relates to aqueous gel compositionscomprising at least one water-soluble agrochemical that are particularlyuseful in maximizing agrochemical uptake and/or translocation intotreated plants and minimizing agrochemical loss to the environment, andto methods of confined application of the agrochemical.

BACKGROUND OF THE INVENTION

Agrochemicals, such as herbicides, are typically formulated as diluteaqueous tank mix formulations that are delivered to plant foliage in anover-the-canopy broadcast application. Problematically, a significantportion of the broadcast application either misses the target plantfoliage or drips off the foliage after application. Further, prior arttank mix compositions dry quickly after foliage application therebyproviding only a limited time period for pesticidal transfer into theplant. Consequently, inefficient pesticidal use and concomitantenvironmental contamination occur. Typically, less than about 10% ofbroadcast applied pesticide is actually taken up into the target plant,with the remainder constituting pesticide waste that remains in thefield.

Thus, there is a need for agrochemical compositions and methods forapplication to plants thereof that provide enhanced agrochemicalretention on plant foliage, increased efficiency in transfer ofagrochemicals to the plants, and minimized agrochemical loss to theenvironment.

SUMMARY OF THE INVENTION

Among the various aspects of the present invention is the provision ofgel compositions comprising at least one herbicide, the compositionsproviding significantly-enhanced retention times on plant foliage,minimum wastage of herbicide and an increase in the herbicidal componenttaken up by a plant.

Briefly, therefore, the present invention is directed to agrochemicalgel compositions comprising from 0.1 to 5 percent by weight on an acidequivalent basis of a water-soluble agrochemical component comprising atleast one water-soluble agrochemical, from 0.1 to 5 percent by weight ofa polymeric gel forming agent component comprising at least onepolymeric gel forming agent, and from 85 to 98 percent by weight water.The tan (delta) of the gel composition is less than 1 as measured byoscillation frequency sweep rheometric measurements between about 0.1and about 600 rad/sec at 0.2 Pa and 1 Pa as measured using cone andplate viscometer method with a 60 mm 2° acrylic cone and plate at 20° C.The yield point of the gel composition is at least about 50 dyne/cm².

The present invention is further directed to a method for confinedapplication of an agrochemical to plants, the method comprising applyingthe agrochemical gel composition to the plants.

The present invention is still further directed to a method of confinedapplication of a water-soluble herbicide to unwanted plants, the methodcomprising applying a gel composition comprising a water-solubleherbicide to the unwanted plants.

The present invention is yet further directed to a method of confinedapplication of a glyphosate herbicide to unwanted plants, the methodcomprising applying a gel composition comprising glyphosate herbicide tothe unwanted plants.

The present invention is further directed to a method of confinedapplication of a glufosinate herbicide to unwanted plants, the methodcomprising applying a gel composition comprising glufosinate,glufosinate-P, or a salt or ester thereof to the unwanted plants.

The present invention is further directed to a method of confinedapplication of an ALS or AHAS inhibitor herbicide to unwanted plants,the method comprising applying a gel composition comprising at least oneALS or AHAS inhibitor herbicide to the unwanted plants.

The present invention is further directed to a method of confinedapplication of an auxin herbicide to unwanted plants, the methodcomprising applying a gel composition comprising at least one auxinherbicide to the unwanted plants.

Other objects and features will be in part apparent and in part pointedout hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph depicting the viscosity of a glyphosate gelcomposition of the present invention as a function of shear rate. Thedata were obtained according to the method described in Example 1.

FIG. 2 is a graph depicting the viscosity of a glyphosate gelcomposition of the present invention as a function of oscillationfrequency sweep at 0.2 Pa stress. The data were obtained according tothe method described in Example 1.

FIG. 3 is a graph depicting G′, G″ and tan (delta) for a glyphosate gelcomposition of the present invention as a function of oscillationfrequency sweep at 0.2 Pa stress. The data were obtained according tothe method described in Example 1.

FIG. 4 is a graph depicting the viscosity of a glyphosate gelcomposition of the present invention as a function of oscillationfrequency sweep at 1 Pa stress. The data were obtained according to themethod described in Example 1.

FIG. 5 is a graph depicting G′ and G″ for a glyphosate gel compositionof the present invention as a function of oscillation frequency sweep at2 Pa stress. The data were obtained according to the method described inExample 1.

FIG. 6 is a graph depicting tan (delta) for a glyphosate gel compositionof the present invention as a function of oscillation frequency sweep at2 Pa stress. The data were obtained according to the method described inExample 1.

FIG. 7 is a graph depicting tan (delta) for glyphosate gel compositionsof the present invention as a function of oscillation frequency sweep at1% strain. The data were obtained according to the method described inExample 1.

FIG. 8 is a graph depicting the viscosity of glyphosate gel compositionsof the present invention as a function of Brookfield DV-II viscometer #3spindle RPM as measured at 25° C. The data were obtained according tothe method described in Example 1.

Corresponding reference characters indicate corresponding partsthroughout the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance with the present invention, aqueous agrochemical gelcompositions comprising at least one water-soluble agrochemical and atleast one gel-forming agent for direct application to plant foliage areprovided. The compositions are confined to and are retained on plantfoliage for significantly longer periods than is typicallycharacteristic of compositions known in the art, minimize loss of theagrochemical to the environment and maximize agrochemical contact timeon the plant foliage. Moreover, the aqueous gels of the presentinvention retain water for an extended period of time as compared totank mixes known in the art thereby providing enhanced agrochemicaluptake into plants. High agrochemical (e.g., herbicidal) efficacy isachieved even in absence of a surfactant. The compositions of thepresent invention allow for selective and directed application to smallareas, such as to individual plants, and are therefore particularlyuseful for lawns and gardens.

For purposes of the present invention, agrochemicals include herbicides,plant growth regulators, acaricides, insecticides, virucides, algicides,bactericides, fungicides, nematicides, herbicide safeners, plantactivators and synergists, salts and esters thereof, racemic mixturesand resolved isomers thereof, and mixtures and combinations thereof. Insome embodiments, the agrochemical is a pesticide such as a herbicide,insecticide, algicide, bactericide, fungicide or nematicide. Althoughreference is herein made to the herbicide glyphosate, one skilled in theart will understand that the principles of the present invention applyto agrochemicals in general, and the invention is not limited toglyphosate herbicidal compositions.

For broadcast applied herbicides, typically only 10% of the herbicide istransferred into the plant (i.e., uptake) after making contact withplant foliage. The combination of improved foliar retention andresistance to drying provided by the gel compositions of the presentinvention allow for greater than 10% uptake of the herbicide componentin the gel composition into the plant including 15%, to as much as 50%uptake into the plant. Therefore, the gel compositions of the presentinvention allow for a more efficient uptake of the herbicide into theplants and/or translocation within the plant to more effectively killthe plants at reduced application rates in kilograms of herbicide perhectare.

The aqueous gel compositions of the present invention are preferablypseudoplastic, elastic and possess a relatively high stationaryviscosity. The high stationary viscosity of the gel compositions of theinstant invention facilitates the tendency of the gels to be retained onthe plant foliage. The pseudoplastic nature of the gel compositionsprovides for low viscosity under elevated stress or shear conditionsthereby enabling ease of application, for example, during pumping,spraying, brushing or roll-on application. The high stationary viscosityof the gels then returns under low or no stress (shear) conditions, suchas after the compositions are applied to plant foliage. The elasticnature of the gels enhances retention on plant foliage. Embodiments ofthe present invention that do not comprise one or more water-insolubleagrochemicals are typically single phase or microemulsions. Embodimentsof the present comprising one or more water-insoluble agrochemicals aretypically two phase compositions including suspensions and emulsions.

In some embodiments, the compositions of the present invention compriseat least one water-soluble herbicide. For purposes of the presentinvention, water-soluble herbicides are defined as having a solubilityof at least 1 gram per liter at 25° C. and water-insoluble herbicidesare defined as having a solubility of less than 1 gram per liter at 25°C. Suitable water-soluble herbicides are selected from acetyl CoAcarboxylase (ACCase) inhibitors, acetolactate synthase (ALS) oracetohydroxy acid synthase (AHAS) inhibitors, photosystem II inhibitors,photosystem I inhibitors, protoporphyrinogen oxidase (PPG or Protox)inhibitors, carotenoid biosynthesis inhibitors, enolpyruvylshikimate-3-phosphate (EPSP) synthase inhibitors, glutamine synthetaseinhibitors, dihydropteroate synthetase inhibitors, mitosis inhibitors,synthetic auxins, auxin transport inhibitors, nucleic acid inhibitors,and certain unclassified herbicides, and water-soluble derivativesthereof. In some embodiments, water-soluble herbicides are selected fromACCase inhibitors, ALS or AHAS inhibitors, photosystem II inhibitors,PPG inhibitors, carotenoid biosynthesis inhibitors, EPSP synthaseinhibitors, dihydropteroate synthetase inhibitors, mitosis inhibitors,synthetic auxins, auxin transport inhibitors and nucleic acidinhibitors. For purposes of the present invention, derivatives of aherbicide include salts, esters, or compounds which are converted theherbicide in plant tissues or which otherwise provide the activeherbicide or anions or cations thereof.

Examples of suitable water-soluble herbicides include, withoutrestriction, 2,4-D, 2,4-DB, acifluorfen, aminopyralid, amitrole, asulam,azimsulfuron, beflubutamide, benazolin, bentazon, bispyribac-sodium,bromacil, carbetamide, carfentrazone-ethyl, chlorimuron-ethyl,chlorsulfuron, cinosulfuron, clopyralid, dicamba, dichlorprop, diclofop,diclopyr, difenzoquat, dimethenamid, dimethipin, diquat, DSMA,endothall, ethoxysulfuron, floramsulfuron, florasulam,flucarbazone-sodium, flumetsulam, fluroxypyr, fosamine, glyphosate,glufosinate, glufosinate-P, halosulfuron-methyl, hexazinone,imazamethabenz-m, imazamox, imazapic, imazapyr, imazaquin, imazethapyr,iodosulfuron, MCPA, MCPB, mecoprop, mecoprop-P, MSMA, naptalam,nicosulfuron, paraquat, water-soluble, agronomically acceptable salts offatty acids predominantly comprising C₈ to C₁₂ saturated, straight orbranched chain fatty acids (e.g., water-soluble, agronomicallyacceptable salts of pelargonic acid), penoxsulam, picloram,primisulfuron-methyl, propoxycarbazone-sodium, prosulfuron,pyrithiobac-sodium, sethoxydim, sulfentrazone, sulfosulfuron,tebuthiuron, tepraloxydim, thifensulfuron-methyl, tralkoxydim,triasulfuron, tribenuron-methyl, triclopyr, trifloxysulfuron andtriflusulfuron-methyl, agriculturally acceptable salts or esters of anyof these herbicides, racemic mixtures and resolved isomers thereof, andmixtures and combinations thereof.

For the purposes of the present invention, “agriculturally acceptablesalts” are generally defined as salts that provide desired solubility,bioefficacy, toxicity and environmental safety characteristics for theintended use. Typical cations for the herbicide salts of the presentinvention include, without restriction, sodium, potassium,monoethanolamine (MEA), dimethylamine (DMA), isopropylamine (IPA),trimethylsulfonium (TMS) diethylammonium (DEA), triethanolamine (TEA),diglycolamine (DGA), lithium, and ammonium. Typical anions for theformation of herbicide salts include, without restriction, chlorine,bromine, fluorine and acetate. Typical esters include, withoutrestriction, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl,isooctyl, ethylhexyl, ethoxyethyl, butoxyethyl, butoxypropyl andoctanoate. Examples of resolved isomer herbicides include, withoutrestriction, glufosinate-P and mecoprop-P. As used herein, where anherbicide or other agrochemical is referred to by name, such asglyphosate or glufosinate, it is understood that agriculturallyacceptable salts, esters, resolved isomers and other derivatives of theagrochemical are included.

In some embodiments of the present invention, the water-solubleherbicide is selected from ALS or AHAS inhibitors, an EPSP inhibitor, aglutamine synthetase inhibitor, synthetic auxins, Photosystem Iinhibitors, and combinations thereof. More particularly, thewater-soluble herbicide can be selected from (i) synthetic auxinsincluding 2,4-D, aminopyralid, clopyralid, dicamba, fluroxypyr,mecoprop, mecoprop-P, picloram and triclopyr, (ii) the Photosystem Iinhibitors diquat and paraquat, (iii) the EPSP inhibitor glyphosate,(iv) the glutamine synthetase inhibitor glufosinate and (v) ALS or AHASinhibitors including imazamethabenz-m, imazamox, imazapic, imazapyr,imazaquin and imazethapyr, agriculturally acceptable salts or esters ofany of these herbicides, racemic mixtures and resolved isomers thereof,and mixtures thereof. In some other embodiments, the water-solubleherbicide is glyphosate or a salt or ester thereof.

In some other embodiments of the present invention, the water-solubleherbicide is selected from ALS or AHAS inhibitors, an EPSP inhibitor,synthetic auxins, and combinations thereof. More particularly, thewater-soluble herbicide can be selected from (i) synthetic auxinsincluding 2,4-D, aminopyralid, clopyralid, dicamba, fluroxypyr,mecoprop, mecoprop-P, picloram and triclopyr, (ii) the EPSP inhibitorglyphosate, and (iii) ALS or AHAS inhibitors including imazamethabenz-m,imazamox, imazapic, imazapyr, imazaquin and imazethapyr, agriculturallyacceptable salts or esters of any of these herbicides, racemic mixturesand resolved isomers thereof, and mixtures thereof. In some preferredembodiments, the herbicidal gel compositions of the present inventionincluding glyphosate or other systemic herbicide are free of certaincontact herbicides (e.g., diquat and other bipyridyliums and diphenylethers) that may tend to undermine the systemic herbicides effectivenessby inducing too much damage to the foliar tissues of the plant afterprolonged contact with the gel.

In some other embodiments, the water-soluble herbicide includesglyphosate or a salt or ester thereof. In some preferred embodiments,the herbicidal gel compositions of the present invention includingglyphosate or a salt thereof are free of glofosinate and other activeingredients that may have a tendency to exhibit glyphosate antagonism.

In some embodiments of the present invention, the herbicide isglyphosate, or a salt or ester thereof and the compositions furthercomprise at least one water-soluble co-herbicide selected from one ormore of ALS or AHAS inhibitors, a glutamine synthetase inhibitor andsynthetic auxins. More particularly, in some water-soluble co-herbicideembodiments of the present invention, the co-herbicide combinationincludes glyphosate and glufosinate (hereinafter referring to both theracemic mixture and glufosinate-P); glyphosate and dicamba and/or 2,4-D;glyphosate and one or more of imazamethabenz-m, imazamox, imazapic,imazapyr, imazaquin and imazethapyr; glyphosate, glufosinate and dicambaand/or 2,4-D; glyphosate, glufosinate, and one or more ofimazamethabenz-m, imazamox, imazapic, imazapyr, imazaquin andimazethapyr; glyphosate, glufosinate, dicamba and/or 2,4-D, and one ormore of imazamethabenz-m, imazamox, imazapic, imazapyr, imazaquin andimazethapyr; or glyphosate, dicamba and/or 2,4-D, glufosinate, and oneor more of imazamethabenz-m, imazamox, imazapic, imazapyr, imazaquin andimazethapyr.

In some other embodiments of the present invention, the herbicide isglyphosate, or a salt or ester thereof and the compositions furthercomprise at least one water-soluble co-herbicide selected from one ormore of ALS or AHAS inhibitors and synthetic auxins. More particularly,in some water-soluble co-herbicide embodiments of the present invention,the co-herbicide combination includes glyphosate and dicamba and/or2,4-D; glyphosate and one or more of imazamethabenz-m, imazamox,imazapic, imazapyr, imazaquin and imazethapyr; or glyphosate, dicambaand/or 2,4-D, and one or more of imazamethabenz-m, imazamox, imazapic,imazapyr, imazaquin and imazethapyr. In some other embodiments of thepresent invention, the herbicide is glyphosate, or a salt or esterthereof and the compositions further comprise at least onewater-soluble, agronomically acceptable salt of a fatty acidpredominantly comprising C₈ to C₁₂ saturated, straight or branched chainfatty acids (e.g., water-soluble, agronomically acceptable salts ofpelargonic acid).

In some embodiments of the present invention, at least onewater-insoluble herbicide may be optionally added to the gels. Examplesof suitable water-insoluble herbicides include, without restriction,acetochlor, acifluorfen, aclonifen, alachlor, ametryn, anilofos,atrazine, azafenidin, benfluralin, bensulfuron-methyl, bensulide,benzofenap, bifenox, bromoxynil, butachlor, butroxydim, butylate,cafenstrole, chlomethoxyfen, chlorbromuron, chloridazon, chlornitrofen,chlorotoluron, chlorthal-dimethyl, chlorthiamid, cinmethylin, clethodim,clodinafop-propargyl, cloransulam-methyl, cyanazine, cycloate,cyclosulfamuron, cycloxydim, cyhalofop-butyl, desmedipham, desmetryn,dichlobenil, diflufenican, dimefuron, dimepiperate, dimethachlor,dinitramine, dinoterb, dithiopyr, diuron, EPTC, esprocarb,ethalfluralin, ethametsulfuron-methyl, ethofumesate, fenoxaprop-ethyl,fentrazamide, fluazifop-butyl, fluchloralin, flufenacet,flumiclorac-pentyl, flumioxazin, fluometuron, fluorochloridone,fluoroglycofen, flupyrsulfuron- methyl-sodium, fluridone,fluroxypyr-1-methylheptyl, flurtamone, fluthiacet-methyl, fomesafen,foramsulfuron, furyloxyfen, haloxyfop-methyl, imazosulfuron, ioxynil,isoproturon, isoxaben, isoxaflutole, lactofen, lenacil, linuron,mefenacet, metazachlor, methabenzthiazuron, metobromuron, metolachlor,metosulam, metoxuron, metribuzin, molinate, monolinuron, napropamide,nitrofen, nitrofluorfen, norflurazon, oryzalin, oxadiargyl, oxadiazon,oxasulfuron, oxyfluorfen, pebulate, fatty acids predominantly comprisingC₈ to C₁₂ saturated, straight or branched chain fatty acids (e.g.,pelargonic acid), pelargonic acid, pendimethalin, phenmedipham,pretilachlor, prodiamine, prometon, prometryn, propachlor, propanil,propaquizafop, propisochlor, propyzamide, prosulfocarb,pyraflufen-ethyl, pyrazolynate, pyrazon, pyrazosulfuron-ethyl,pyrazoxyfen, pyridate, quinclorac , quinmerac, quizalofop-ethyl,rimsulfuron, siduron, simazine, simetryn, sulcotrione, sulfometuron,terbacil, terbumeton, terbuthylazine, terbutryn, thenylchlor, thiazopyr,thiobencarb, triallate, trietazine, trifluralin and vernolate,agriculturally acceptable salts or esters of any of these herbicides,racemic mixtures and resolved isomers thereof, and mixtures andcombinations thereof.

In some embodiments of the present invention, the water-insolubleherbicide is selected from atrazine, diuron, acetochlor, alachlor,butachlor, dithiopyr, metazochlor, metolachlor (and S-metolachlor),pretilachlor, propachlor, propisochlor and thenylchlor, agriculturallyacceptable salts or esters of any of these herbicides, racemic mixturesand resolved isomers thereof, and mixtures and combinations thereof.

In some other embodiments, the water-soluble herbicide is selected from2,4-D, aminopyralid, clopyralid, dicamba, diquat, fluroxypyr,glyphosate, glufosinate, glufosinate-P, mecoprop, mecoprop-P,imazamethabenz-m, imazamox, imazapic, imazapyr, imazaquin, imazethapyr,paraquat, picloram and triclopyr, and mixtures thereof and thewater-insoluble herbicide is selected from atrazine, diuron, acetochlor,alachlor, butachlor, dithiopyr, metazochlor, metolachlor (andS-metolachlor), pretilachlor, propachlor, propisochlor and thenylchlor.In some other embodiments, the water-soluble herbicide is glyphosate andthe water-insoluble herbicide is selected from one or more of atrazine,diuron, acetochlor, alachlor, butachlor, dithiopyr, metazochlor,metolachlor (and S-metolachlor), pretilachlor, propachlor, propisochlorand thenylchlor. The above-described water-soluble and water-insolubleherbicides include agriculturally acceptable salts or esters thereof,and racemic mixtures and resolved isomers thereof.

Regardless of the particular water-soluble herbicide, combination ofwater-soluble herbicides, or combinations of one or more water-solubleherbicides and at least one water-insoluble herbicide present in theaqueous gel compositions of the present invention, the total herbicideconcentration is from about 1 to about 50 (“g a.e./L”), for example,from about 1 to about 30 g a.e./L, from about 5 to about 50 g.e./L),from about 5 to about 45 g a.e./L, from about 5 to about 40 g a.e./L,from about 5 to about 35 g a.e./L, about 5 to about 30 g a.e./L, fromabout 5 to about 25 g a.e./L, from about 5 to about 20 g a.e./L, or fromabout 5 to about 15 g a.e./L, in particular, 1, 5, 10, 15, 20, 25, 30,35, 40, 45 or even 50 g a.e./L. Expressed alternatively, theconcentration is most broadly from about 0.1 to about 5 percent byweight (wt %), from about 0.1 to about 3 wt %, from about 0.5 to about 5wt %, from about 0.5 to about 4.5 wt %, from about 0.5 to about 4 wt %,from about 0.5 to about 3.5 wt %, from about 0.5 to about 3 wt %, fromabout 0.5 to about 2.5 wt %, from about 0.5 to about 2 wt %, or fromabout 0.5 to about 1.5 wt % on an acid equivalent basis. In the case ofglyphosate in combination with one or more co-herbicides, the weightratio of glyphosate to total co-herbicide, on an acid equivalent basis,is typically from about 10:1 to about 1:10, from about 5:1 to about 1:5,from about 3:1 to about 1:3 or from about 2:1 to about 1:2.

The compositions of the present invention have a total water content offrom about 80 to about 98 percent by weight (wt %) water, from about 85to about 98 wt % water, from about 90 to about 98 wt %, from about 94 toabout 97.5 wt % water, from about 94 to about 98 wt % water, from about95 to about 97.5 wt % water, or from about 95 to about 98 wt % water.

The gel forming agents for use in the instant invention are polymericmaterials selected to achieve the rheological characteristics of thecompositions of the present invention. The gel compositions of thepresent invention may be rheologically characterized by tan (delta),static or stationary viscosity, yield point and pseudoplasticity.Compositions of the present invention having a tan (delta) value in thepreferred range will retain sufficient energy when a stress or strain isapplied, for example by application methods such as rolling, brushing orpassing the composition through a nozzle, to return to its previouscondition and exhibit excellent stand-up when the stress or strain isremoved. The compositions will also have a high cohesive property,namely, when a shear or strain is applied to a portion of thecomposition to cause it to flow, the surrounding portions will follow.As a result of this cohesiveness, the gel compositions of the presentinvention exhibit good retention on plant foliage and resist run-off.Moreover, the cohesiveness contributes to the physical (phase) stabilityof the gel compositions and resistance to phase separation of anyundissolved suspended particles by providing a resistance to movement ofthe particles due to the strain exerted by a particle on the surroundfluid medium. The gel forming agents are preferably hydrophilic.

Tan (delta) is expressed as G″/G′ where G″ is the viscous (loss) modulusand G′ is the elastic (storage) modulus of the gel. By way of furtherexplanation, the elastic (storage) modulus G′ is a measure of the energystored and retrieved when a strain is applied to the composition whileviscous (loss) modulus G″ is a measure to the amount of energydissipated as heat when strain is applied. Expressed another way, G′ isa measure of the ability of a composition to store recoverable energy.This energy storage can be the result of the ability of a complexpolymer, structural network, or a combination of these to recover storedenergy after a deformation. G″ is a measure of the unrecoverable energywhich has been lost due to viscous flow. A tan (delta) in the preferredrange indicates that the elastic component of the gel predominates.

Tan (delta) can be measured by methods known to those skilled in theart. For instance, tan (delta) may be determined by using a mechanicalspectrometer, such as model RMS-800, available from Rheometrics, Inc. inPiscataway, N.J., USA. In the evaluation, a disk-like compositionsample, for example measuring about 2.5 mm in thickness and about 25 mmin diameter, is placed between opposed, axially spaced apart,radially-extending surfaces and the sample is in connection with eachsurface thereby filling a portion of the axial spacing between thesurfaces. At a selected temperature (for instance 25° C.), one of thesurfaces then is rotated about the axial direction relative to the otherat a selected oscillating frequency (for instance one Radian per second)in order to place the test specimen under shear conditions. The torqueresulting from the shear is measured. The shear may be steady shear, inwhich case the measured torque is constant, or the shear may be dynamicshear, in which case the measured torque changes continuously with time.The measured torque is proportional to the viscous, or loss component ofthe modulus (G″) of the material. Typically, the shear is steady shear,meaning the measured torque, and thus G″, is constant at the giventemperature. As a result of the nature of the forces applied to the testspecimen in this procedure, the test specimen has a tendency to expandaxially, thereby placing axially directed forces upon the relativelyrotating surfaces to which the specimen is coupled. This axial forceexerted upon the surfaces by the test specimen under shear conditions isproportional to the elastic, or storage component of the modulus (G′) ofthe material. The parameter tan (delta) is then calculated as G″ dividedby G′ at the stated temperature and oscillating frequency. The gelcompositions of the present invention preferably have a tan(delta) valueof less than 1, less than 0.9, less than 0.8, less than 0.7, less than0.6, less than 0.5, less than 0.4, or less than 0.3, for example, 0.9,0.8, 0.7 ,0.6, 0.5, 0.4, 0.3, 0.2, 0.1 or 0.05 and ranges thereof, suchas from 0.05 to 0.9, from 0.05 to 0.8, 0.05 to 0.7, 0.05 to 0.6, 0.05 to0.5, 0.05 to 0.4 or from 0.05 to 0.3.

In some embodiments of the present invention, tan delta is determined byoscillation frequency sweep rheometric measurements between about 0.1and about 600 rad/sec at 0.2 Pa and 1 Pa as measured on a TA rheometerwith a 60 mm 2° acrylic cone and plate at 20° C. G′ and G″ in Pa aremeasured and tan (delta) is calculated as G″/G′.

The compositions of the present invention preferably are pseudoplasticgels defined as having a viscosity that decreases with increasing shearrate (also termed shear thinning). Such gels exhibit a relatively lowviscosity under high-shear conditions and a relatively high viscosityunder low or no shear conditions. Consequently, the gels of the presentinvention have a high stationary viscosity (i.e. viscosity when notsubjected to shear), but low viscosity when subjected to shear therebyresulting in a thin (low viscosity) solution that can be easilydispensed and applied to plant foliage, for example, as a fine spray orby direct application through, for instance, rolling or brushing.Stationary viscosity can also be termed “yield value” or “maximumviscosity” wherein each term refers to a measure of a gel's initialresistance to flow under shear. After application to plant foliage, aperfectly pseudoplastic gel regains all of its stationary viscosity inresponse to the absence of shear. The high stationary viscosity providesgood foliage surface cling (inhibits dripping or flow of thecompositions from non-horizontal leaf surfaces) and enhances the abilityof the applied compositions to remain on the leaf after deposition, andnot be dislodged or washed away from the surface during ordinaryconditions of use.

Yield point is typically defined as the threshold shear stress that mustbe applied to induce flow of a fluid. The compositions of the presentinvention preferably have a yield point that allows for application of aflowable composition by mechanical methods having relatively low shearstress, such as by brushing or roll-on application, but is yet highenough to ensure that the gel is retained on the foliar tissues once theexternal stress is removed. The yield point of the gel compositions inaccordance with the present invention is preferably at least about 50,75, 100, 125, 150, 175, or at least about 200 dyne/cm², and rangesthereof, for example, such as from about 50 to about 400 dyne/cm², fromabout 50 to about 300 dyne/cm², from about 100 to about 400 dyne/cm² orfrom about 100 to about 300 dyne/cm². Like tan (delta), yield point fora gel composition can be readily measured using conventional equipmentand methods known to those skilled in the art. Suitable means fordetermining yield point are set forth in Example 1.

In some embodiments of the invention, the gel compositions may exhibitsome degree of thixotropy, i.e, the gels are not perfectlypseudoplastic, wherein viscosity is reduced by shear, as describedabove, but in contrast to a perfectly pseudoplastic liquid (whichregains all of its stationary viscosity when the shear stress isremoved), the viscosity of a thixotropic gel does not immediately returnto its original value when the shear stress is removed. Whilepseudoplastic properties are the most desired for this invention, almostall compositions will exhibit some acceptable degree of thixotropy.

Viscosity of the gels of the present invention can be measured bymethods known to those skilled in the rheological arts. For example,cone and plate-type viscometers as available from Rheometrics, Haake andBrookfield are suitable for viscosity measurement. Similarly,spindle-type viscometers as available from Haake or Brookfield can beused. For instance, stationary viscosity could be measured with aBrookfield RVT rotational viscosimeter fitted to a HELIPATH stand andwith a TA spindle, at 1 r.p.m. and 25° C. In an optional method formeasuring stationary viscosity of the pseudoplastic gels of the presentinvention, viscosity could be measured at varying shear rates. Azero-shear viscosity can be then be accurately estimated by linearregression of the collected viscosity versus shear data. A stationaryviscosity measured as a function of shear rate (using, for instance, anAR 200 Advanced Rheometer (available from TA Instruments, Ltd.) with a60 mm 2° acrylic cone and plate at 20° C. with an oscillating frequencyof 100 rad/s) of greater than 2,000 mPa second is preferred, such asabout 3,000, 4,000, 5,000, 10,000, 20,000, 30,000, 40,000, 50,000,75,000, 100,000 or 150,000 mPa second. Viscosity ranges thereof, such asfrom about 2,000, 3,000, 4,000, 5,000, 10,000, 25,000 or 50,000 to about150,000 mPa second, from about 2,000, 3,000, 4,000, 5,000, 10,000,25,000 or 50,000 to about 100,000 mPa second, or from about 2,000,3,000, 4,000, 5,000, 10,000, 25,000 to about 50,000 mPa second arepreferred.

Gel forming agents of the present invention include: polyacrylic acids(CARBOPOL); polycarboxylic acids such as poly(l-carboxyethylene),carboxypolymethylenes prepared from acrylic acid cross-linked with allylethers of (polyalkyl)sucrose or pentaerythritol (such as CARBOPOL940/941/980/981/1342/1382 and carbamer polymers such as carbomer934P/974P); polyacrylamides; polyacrylates including CARBOPOL AQUA 30,sodium acrylate polymers (AQUAKEEP J-550/J-400) and alkyl acrylatepolymers (PEMULEN); cellulose polymers such as hydroxypropyl cellulose(KLUCEL), hydroxypropylmethyl cellulose (KLUCEL HF, METHOCEL),hydroxypropylethyl cellulose, hydroxypropylbutyl cellulose,hydroxypropylpentyl cellulose, hydroxyethyl cellulose (NATROSOL),ethylcellulose, carboxymethyl cellulose, hydroxypropylmethyl cellulosephthalate, and cellulose acetate acrylic acid esters;alkoxybutyninpolymers such as polyoxyethylene-polyoxypropylenecopolymers (available from BASF as the PLURONIC line); vinyl polymerssuch as but not limited to carboxyvinyl polymers, polyvinyl pyrrolidone,polyvinyl alcohol, polyvinyl methyl ether, polyvinyl ether, polyvinylsulfonates, and mixtures or copolymers thereof; polyethylene compoundssuch as polyethylene glycol; polysaccharides such as polysucrose,polyglucose or polylactose, and salts thereof; polyethylene oxidepolymers; poly(ethylene oxide)-co-poly(propylene oxide) blockcopolymers; poly(ethyloxazoline) polymers; gelatin succinate; naturalgel forming agents including, gellan gum (available commercially asGELRITE, KELCOGEL and GELRITE), dextran, gaur-gum, tragacanth, xanthangum, sodium pectinate, sodium alginate, acacia gum, Irish moss, karayagum, guaiac gum and locust bean gum; natural high molecular weightcompounds including proteins such as casein, gelatin, collagen, albumin;miscellaneous carbohydrates such as cellulose, dextrin, pectin,starches, agar and mannan; and mixtures thereof. These substances may bealso be chemically derivatized (modified), e.g. esterified, etherified,hydrolyzed (e.g. sodium alginate, sodium pectinate, etc.) or saltsthereof (e.g. sodium carboxymethyl cellulose). In some embodiments, thegel forming agent for use in the present invention includes polyacrylicacid (CARBOPOL), carboxylmethyl cellulose or CMC (COYOTE CMC-9000 fromGum Technology), polysucrose (KELZAN, Kelco Corp) or gellan gum.

Generally, the rheological characteristics of the compositions of thepresent invention vary depending on the identity of the gel formingagent, the identity and concentration of the water-soluble herbicidecomponent, on the identity and concentration of the water-insolubleherbicide component (if present) and on the identity and concentrationof a surfactant component (if present). The gel forming agentconcentration, on an active basis, in the compositions of the presentinvention is from about 0.1 to about 5 wt %, from about 1 to about 5 wt%, from about 1 to about 4 wt % from about 1 to about 3 wt %, from about2 to about 5 wt %, from about 2 to about 4 wt % or from about 2 to about3 wt %. As used herein, the active basis concentration of a gel formingagent relates to the concentration of the active gel forming agent inthe gel. For instance, CARBOPOL AQUA 30 polymer contains 30% by weightpolymeric gel forming agent. Therefore, a composition of the presentinvention containing 10% by weight CARBOPOL AQUA 30 would have a gelforming agent concentration, on an active basis, in the composition of3%. Similar calculations may be done for other gel forming agents thatare within the scope of the present invention.

The rheological characteristics of some preferred gel forming agents ofthe present invention are affected by pH. For such pH-responsive gels,it is believed, without being bound to any particular theory, that gelsare formed when the pH approaches the pKa of the pH-responsive gelforming compound. Stated differently, under one theory, it is believedthat a pH-responsive gel reversibly forms in response to a change in thecharging of the polymer chain, which is a chemical reaction where acidicor basic groups on the polymer are ionized or neutralized. For instance,compositions comprising polyacrylic acid gel forming agents will notform a gel at a pH of less than about 5. Composition viscosity rapidlyincreases at a pH of greater than about 7 and a gel is formed. The gelforming behavior of other gel forming agents, such as carboxylmethylcellulose and polysucrose, is generally independent of pH.

The compositions of the present invention typically comprise one or morepreservatives . Preservatives, when used, include, but are not limitedto, biocides such mildewstats and bacteriostats. Examples includemethyl, ethyl and propyl parabens; short chain organic acids (e.g.acetic, lactic and/or glycolic acids); bisguanidine compounds (e.g.Dantagard and/or Glydant); short chain alcohols (e.g. ethanol and/orIPA); 5-chloro-2-methyl -4-isothiazolin-3-one (KATHON GC),2-methyl-4-isothiazolin-3-one (KATHON ICP),5-chloro-2-methyl-4-isothiazolin-3-one (KATHON 886), all available fromRohm and Haas Company; 2-bromo-2-nitropropane 1, 3 diol (BRONOPOL), fromBoots Company Ltd.; propyl-p-hydroxybenzoate (PROXEL CRL), from ICIPLC;1,2-Benzisothiazol-3(2H)-one biocide (PROXEL GXL) from ZenecaSpecialties Co.; o-phenyl-phenol, Na⁺salt (NIPASOL M) from NipaLaboratories Ltd.; 1,2-Benzoisothiazolin-3-one (DOWICIDE A) and1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride (DOWICIL 75),from Dow Chemical Co.; quaternary alkyl ammonium chloride in 2-propanol(ARQUAD 2.8-50) from Akzo Nobel; and2,4,4′-trichloro-2-hydroxydiphenylether (IRGASAN DP 200), fromCiba-Geigy A.G.

Based on experimental evidence to date, it has been discovered that theherbicidal performance of the gels of the present invention is notsignificantly affected by the presence of a surfactant. It is believed,without being bound to any particular theory, that the gels provideenhanced foliar contact time and a reduced drying rate thereby allowingefficient herbicide uptake an/or translocation even in the absence of asurfactant. In comparison, prior art liquid compositions do noteffectively cling to the foliage and dry quickly. Consequently, asurfactant is typically required in such prior art compositions in orderto provide rapid herbicide uptake before the composition drips off ofthe foliage and/or dries. Nonetheless, in some embodiments of thepresent invention, herbicidal efficacy enhancing surfactants known inthe art can optionally be added to the gels. A weight ratio ofherbicide, on an a.e. basis, to surfactant of from 1:1 to 20:1, from 2:1to 10:1 or from 3:1 to 8:1 is preferred.

Alkoxylated tertiary etheramine surfactants for use in the herbicidalcompositions of the present invention have the general structure (1):

wherein R₁ is a hydrocarbyl or substituted hydrocarbyl having from about4 to about 22 carbon atoms; R₂ is a hydrocarbylene having 2, 3, or 4carbon atoms; m is an average number from about 1 to about 10; R₃ and R₄are each independently hydrocarbylene having 2, 3, or 4 carbon atoms; R₅and R₆ are each independently hydrogen or hydrocarbyl having 1 to 4carbon atoms; and the sum of x and y is an average value ranging fromabout 2 to about 60.

R₁ is preferably an alkyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 18 carbon atoms, from about 10 toabout 16 carbon atoms, or from about 12 to about 18 carbons atoms, orfrom about 10 to about 14 carbon atoms. Sources of the R₁ group include,for example, coco or tallow, or R₁ may be derived from synthetichydrocarbyls, such as decyl, dodecyl, tridecyl, tetradecyl, hexadecyl,or octadecyl groups. R₂ may be propylene, isopropylene, or ethylene, andm is preferably from about 1 to 5, such as 2 to 3. R₃ and R₄ may beethylene, propylene, isopropylene, and are preferably ethylene. R₅ andR₆ are preferably hydrogen. The sum of x and y is preferably an averagevalue ranging from about 2 to about 22, such as from about 2 to 10, orabout 2 to 5. In some embodiments, the sum of x and y is preferablybetween about 10 and about 20, for example, about 15.

Specific alkoxylated tertiary etheramine surfactants for use in theherbicidal composition of the present invention include, for example,any of the TOMAH E-Series surfactants, such as TOMAH E-14-2(bis-(2-hydroxyethyl) isodecyloxypropylamine), TOMAH E-14-5 (poly (5)oxyethylene isodecyloxypropylamine), TOMAH E-17-2, TOMAH E-17-5 (poly(5) oxyethylene isotridecyloxypropyl amine), TOMAH E-19-2, TOMAH E-18-2,TOMAH E-18-5 (poly (5) oxyethylene octadecylamine), TOMAH E-18-15, TOMAHE-19-2 (bis-(2-hydroxyethyl) linear alkyloxypropylamine), TOMAH E-S-2,TOMAH E-S-15, TOMAH E-T-2 (bis-(2-hydroxyethyl) tallow amine), TOMAHE-T-5 (poly (5) oxyethylene tallow amine), and TOMAH E-T-15 (poly (15)oxyethylene tallow amine). Another example is Surfonic AGM 550 availablefrom Huntsman Petrochemical Corporation wherein, for formula (1) , R₁₉₁is C₁₂₋₁₄, R₁₉₂ is isopropyl, m is 2, R₁₉₃ and R₁₉₄ are each ethylene,and x+y is 5.

Alkoxylated quaternary etheramine surfactants for use in the herbicidalcompositions of the present invention have the general structure (2):

wherein R₁₁ is a hydrocarbyl or substituted hydrocarbyl having fromabout 4 to about 22 carbon atoms; R₁₂ is a hydrocarbylene having 2, 3,or 4 carbon atoms; m is an average number from about 1 to about 10; R₁₃and R₁₄ are each independently hydrocarbylene having 2, 3, or 4 carbonatoms; R₁₅ and R₁₆ are each independently hydrogen or hydrocarbyl having1 to 4 carbon atoms; and the sum of x and y is an average value rangingfrom about 2 to about 60. R₁₅ is preferably a hydrocarbyl or substitutedhydrocarbyl having from 1 to about 4 carbon atoms, more preferablymethyl. A is a charge balancing counter-anion, such as sulfate,chloride, bromide, nitrate, among others.

R₁₁ is preferably an alkyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 18 carbon atoms, from about 10 toabout 16 carbon atoms, or from about 12 to about 18 carbons atoms, orfrom about 12 to about 14 carbon atoms. Sources of the R₁₁ groupinclude, for example, coco or tallow, or R₁₁ may be derived fromsynthetic hydrocarbyls, such as decyl, dodecyl, tridecyl, tetradecyl,hexadecyl, or octadecyl groups. R₁₂ may be propylene, isopropylene, orethylene, and m is preferably from about 1 to 5, such as 2 to 3. R₁₃ andR₁₄ may be ethylene, propylene, isopropylene, and are preferablyethylene. R₁₅ and R₁₆ are preferably hydrogen. The sum of x and y ispreferably an average value ranging from about 2 to about 22, such asfrom about 2 to 10, or about 2 to 5. In some embodiments, the sum of xand y is preferably between about 10 and about 20, for example, about15.

Specific alkoxylated quaternary etheramine surfactants for use in theherbicidal composition of the present invention include, for example,TOMAH Q-14-2, TOMAH Q-17-2, TOMAH Q-17-5, TOMAH Q-18-2, TOMAH Q-S, TOMAHQ-S-80, TOMAH Q-D-T, TOMAH Q-DT-HG, TOMAH Q-C-15, and TOMAH Q-ST-50.

Alkoxylated etheramine oxide surfactants for use in the herbicidalcompositions of the present invention have the general structure (3):

wherein R₂₁ is a hydrocarbyl or substituted hydrocarbyl having fromabout 4 to about 22 carbon atoms; R₂₂ is a hydrocarbylene having 2, 3,or 4 carbon atoms; m is an average number from about 1 to about 10; R₂₃and R₂₄ are each independently hydrocarbylene having 2, 3, or 4 carbonatoms; R₂₅ and R₂₆ are each independently hydrogen or hydrocarbyl having1 to 4 carbon atoms; and the sum of x and y is an average value rangingfrom about 2 to about 60.

R₂₁ is preferably an alkyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 18 carbon atoms, from about 10 toabout 16 carbon atoms, or from about 12 to about 18 carbons atoms, orfrom about 12 to about 14 carbon atoms. Sources of the R₂₁ groupinclude, for example, coco or tallow, or R₂₁ may be derived fromsynthetic hydrocarbyls, such as decyl, dodecyl, tridecyl, tetradecyl,hexadecyl, or octadecyl groups. R₂₂ may be propylene, isopropylene, orethylene, and m is preferably from about 1 to 5, such as 2 to 3. R₂₃ andR₂₄ may be ethylene, propylene, isopropylene, and are preferablyethylene. R₂₅ and R₂₆ are preferably hydrogen. The sum of x and y ispreferably an average value ranging from about 2 to about 22, such asfrom about 2 to 10, or about 2 to 5. In some embodiments, the sum of xand y is preferably between about 10 and about 20, for example, about15.

Specific alkoxylated etheramine oxide surfactants for use in theherbicidal composition of the present invention include, for example,any of the TOMAH AO-series of surfactants, such as TOMAH AO-14-2, TOMAHAO-728, TOMAH AO-17-7, TOMAH AO-405, and TOMAH AO-455.

Alkoxylated tertiary amine oxide surfactants for use in the herbicidalcompositions of the present invention have the general structure (4):

wherein R₃₁ is a hydrocarbyl or substituted hydrocarbyl having fromabout 4 to about 22 carbon atoms, R₃₂ and R₃₃ are each independentlyhydrocarbylene having 2, 3, or 4 carbon atoms, R₃₄ and R₃₅ are eachindependently hydrogen or hydrocarbyl having 1 to 4 carbon atoms, andthe sum of x and y is an average value ranging from about 2 to about 50.

R₃₁ is preferably an alkyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 18 carbon atoms, and still morepreferably from about 12 to about 18 carbons atoms, for example coco ortallow. R₃₁ is most preferably tallow. R₃₂ and R₃₃ are preferablyethylene. R₃₄ and R₃₅ are preferably hydrogen. The sum of x and y ispreferably an average value ranging from about 2 to about 22, morepreferably between about 10 and about 20, for example, about 15.

Specific alkoxylated tertiary amine oxide surfactants for use in theherbicidal compositions of the present invention include, for example,any of the AROMOX series of surfactants, including AROMOX C/12, AROMOXC/12W, AROMOX DMC, AROMOX DM16, AROMOX DMHT, and AROMOX T/12 DEG.

Alkoxylated tertiary amine surfactants for use in the herbicidalcompositions of the present invention have the general structure (5):

wherein R₄₁ is a hydrocarbyl or substituted hydrocarbyl having fromabout 4 to about 22 carbon atoms, R₄₂ and R₄₃ are each independentlyhydrocarbylene having 2, 3, or 4 carbon atoms, R₄₄ and R₄₅ are eachindependently hydrogen or hydrocarbyl having 1 to 4 carbon atoms, andthe sum of x and y is an average value ranging from about 2 to about 50.

R₄₁ is preferably an alkyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 18 carbon atoms, and still morepreferably from about 12 to about 18 carbons atoms, for example coco ortallow. R₄₁ is most preferably tallow. R₄₂ and R₄₃ are preferablyethylene. R₄₄ and R₄₅ are preferably hydrogen. The sum of x and y ispreferably an average value ranging from about 2 to about 22, morepreferably between about 10 and about 20, for example, about 15.

Specific alkoxylated tertiary amine surfactants for use in theherbicidal compositions of the present invention include, for example,Ethomeen T/12, Ethomeen T/20, Ethomeen T/25, Ethomeen T/30, EthomeenT/60, Ethomeen C/12, Ethomeen C/15, and Ethomeen C/25, each of which areavailable from Akzo Nobel.

Alkoxylated quaternary amine surfactants for use in the herbicidalcompositions of the present invention have the general structure (6):

wherein R₅₁, R₅₂, R₅₃, x and y are as described above for thealkoxylated tertiary amine surfactants of structure (5), i.e., R₅₁ is ahydrocarbyl or substituted hydrocarbyl having from about 4 to about 22carbon atoms, R₅₂ and R₅₃ are each independently hydrocarbylene having2, 3, or 4 carbon atoms, R₅₄ and R₅₅ are each independently hydrogen orhydrocarbyl having 1 to 4 carbon atoms, and the sum of x and y is anaverage value ranging from about 2 to about 50. R₅₄ is preferably ahydrocarbyl or substituted hydrocarbyl having from 1 to about 4 carbonatoms, more preferably methyl. X is a charge balancing counter-anion,such as sulfate, chloride, bromide, nitrate, among others.

R₅₁ is preferably an alkyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 18 carbon atoms, and still morepreferably from about 12 to about 18 carbons atoms, for example coco ortallow. R₅₁ is most preferably tallow. R₅₂ and R₅₃ are preferablyethylene. R₅₄ and R₅₅ are preferably hydrogen. The sum of x and y ispreferably an average value ranging from about 2 to about 22, morepreferably between about 10 and about 20, for example, about 15.Specific alkoxylated quaternary amine surfactants for use in theherbicidal composition of the present invention include, for example,Ethoquad T/12, Ethoquad T/20, Ethoquad T/25, Ethoquad C/12, EthoquadC/15, and Ethoquad C/25, each of which are available from Akzo Nobel.

An example of an alkoxylated polyamine surfactant for use in theherbicidal compositions of the present invention is a surfactant havingthe general structure (7):

wherein R₆₁ is an alkyl or alkenyl radical containing 6 to 25 carbonatoms and from 0 to 3 carbon-carbon double bonds; R₆₂ is —OCH₂CH₂CH₂—,—C(═O)OCH₂CH₂—, —C(═O) NHCH₂CH₂CH₂—, or —CH₂—; each occurrence of R₆₄ isindependently —H, —OC(═O)R₁, —SO₃ ⁻A⁺or —CH₂C(═O)O⁻A⁺wherein A⁺is analkali metal cation, ammonium or H⁺; each occurrence of a is from 3 to8; each R₆₃ is independently ethyl, isopropyl or n-propyl; d, e, f and gare each independently from 1 to 20, b is from 0 to 10, c is 0 or 1, thesum of (c+d+e+f) is from (3+b) to 20, and the molecular weight is nomore than about 800. The surfactants of formula (7) can optionally be inthe form of a cation where one or more nitrogen atoms is additionallysubstituted with hydrogen, methyl, ethyl, hydroxyethyl or benzyl and oneor more anions, equal in number to the number of said additionallysubstituted nitrogen atoms and being selected from chloride,methylsulfate and ethylsulfate. The surfactants of formula (7) canfurther optionally be in the form of amine oxides.

Examples of specific alkoxylated polyamine surfactants for use in theherbicidal composition of the present invention are described indescribed in U.S. Pat. No. 6,028,046 (to Arif). Alkoxylated polyaminesurfactants include, for example, ethoxylates of Adogen 560 (N-cocopropylene diamine) containing an average of from 2EO to 20EO, forexample, 4.8, 10 or 13.4EO; ethoxylates of Adogen 570 (N-tallowpropylene diamine) containing an average of form 2EO to 20EO, forexample, 13EO; and ethoxylates of Adogen 670 (N-tallow propylenetriamine) containing an average of from 3EO to 20EO, for example, 14.9EOall of which are available from Witco Corp.

Other polyamine surfactants for use in the herbicidal compositions ofthe present invention have the general structure (8):

wherein R₇₁ is C₈₋₂₀, R₇₂ is C₁₋₄ and n is 2 or 3. Examples ofpolyamines for use in the compositions and methods of the presentinvention include Triamine C (R₇₁ is coco (C₁₀₋₁₄)), R₇₂ is C₃, n is 2and amine number (total mg KOH/g) is 500-525), Triamine OV (R₇₁ is oleyl(vegetable oil) , R₇₂ is C₃, n is 2 and amine number (total mg KOH/g) is400-420), Triamine T (R₇₁ is tallow (C₁₆₋₁₈), R₇₂ is C₃, n is 2 andamine number (total mg KOH/g) is 415-440), Triamine YT (R₇₁ is tallow(C₁₆₋₁₈), R₇₂ is C₃, n is 2 and amine number (total mg KOH/g) is390-415), Triameen Y12D (R₇₁ is dodecyl (C₁₂) , R₇₂ is C₃, n is 2 andamine number (total mg HC1/g is 112-122), Triameen Y12D-30 (R₇₁ isdodecyl (C₁₂), R₇₂ is C₃, n is 2 and amine number (total mg HC1/g is335-365), Tetrameen OV (R₇₁ is oleyl (vegetable oil), R₇₂ is C₃, n is 3and amine number (total mg KOH/g) is 470-500), Tetrameen T (R₇₁ istallow (C₁₆₋₁₈), R₇₂ is C₃, n is 3 and amine number (total mg KOH/g) is470-495), wherein each is available from Akzo Nobel.

Sulfate surfactants for use in the herbicidal compositions of thepresent invention have the general structure (9a-c):

wherein compounds of formula (9a) are alkyl sulfates, compounds offormula (9b) are alkyl ether sulfates and compounds of formula (9c) arealkyl aryl ether sulfates. R_(n) is a hydrocarbyl or substitutedhydrocarbyl having from about 4 to about 22 carbon atoms, each R₈₂ isindependently ethyl, isopropyl or n-propyl and n is from 1 to about 20.M is selected from an alkali metal cation, ammonium, an ammoniumcompound or H⁺. Examples of alkyl sulfates include sodium C₈₋₁₀ sulfate,sodium C₁₀₋₁₆ sulfate, sodium lauryl sulfate, sodium C₁₄₋₁₆ sulfate,diethanolamine lauryl sulfate, triethanolamine lauryl sulfate andammonium lauryl sulfate. Examples of alkyl ether sulfates include sodiumC₁₂₋₁₅ pareth sulfate (1 EO) , ammonium C₆₋₁₀ alcohol ether sulfate (3EO) , sodium C₆₋₁₀ alcohol ether sulfate (3 EO), isopropylammonium C₆₋₁₀alcohol ether sulfate (3 EO), ammonium C₁₀₋₁₂ alcohol ether sulfate (3EO), sodium lauryl ether sulfate (3 EO). Examples of alkyl aryl ethersulfates include sodium nonylphenol ethoxylate sulfate (4 EO), sodiumnonylphenol ethoxylate sulfate (10 EO) , Witcolate™ 1247H (C₆₋₁₀, 3E0,ammonium sulfate), WITCOLATE 7093 (C₆₋₁₀, 3E0, sodium sulfate),WITCOLATE 7259 (C₈₋₁₀ sodium sulfate) , WITCOLATE 1276 (C₁₀₋₁₂, 5E0,ammonium sulfate), WITCOLATE LES-60A (C₁₂₋₁₄, 3E0, ammonium sulfate),WITCOLATE LES-60C (C₁₂₋₁₄, 3E0, sodium sulfate), WITCOLATE 1050 (C₁₂₋₁₅,10EO, sodium sulfate), WITCOLATE WAQ (C₁₂₋₁₆ sodium sulfate), WITCOLATED-51-51 (nonylphenol 4EO, sodium sulfate) and WITCOLATE D-51-53(nonylphenol 10EO, sodium sulfate).

Sulfonate surfactants for use in the herbicidal compositions of thepresent invention correspond to sulfate structures (9a) through (9c)above except the R-substituted moiety is attached directly to the sulfuratom, for instance R₈₁SO₃ ^(—). Examples of sulfonate surfactantsinclude, for example, Witconate™ 93S (isopropylamine of dodecylbenzenesulfonate), WITCONATE NAS-8 (octyl sulfonic acid, sodium salt),WITCONATE AOS (tetradecyl/hexadecyl sulfonic acid, sodium salt),WITCONATE 60T (linear dodecylbenzene sulfonic acid, triethanolaminesalt) and WITCONATE 605a (branched dodecylbenzene sulfonic acid,N-butylamine salt).

Phosphate esters of alkoxylated alcohol surfactants for use in theherbicidal compositions of the present invention have the generalmonoester structure (10a) and the general diester structure (10b):

wherein R₉₁ is a hydrocarbyl or substituted hydrocarbyl having fromabout 4 to about 22 carbon atoms; R₉₂ is a hydrocarbylene having 2, 3,or 4 carbon atoms; m is an average number from about 1 to about 60; andR₉₃ and R₉₄ are each independently hydrogen or a linear or branchedchain alkyl having from 1 to about 6 carbon atoms.

R₉₁ is preferably an alkyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 20 carbon atoms, or an alkylphenylhaving from about 4 to about 22 carbon atoms, more preferably from about8 to about 20 carbon atoms. Sources of the R₉₁ group include, forexample, coco or tallow, or R₉₁ may be derived from synthetichydrocarbyls, such as decyl, dodecyl, tridecyl, tetradecyl, hexadecyl,or octadecyl groups. R₉₂ may be propylene, isopropylene, or ethylene,and is preferably ethylene. m is preferably from about 9 to about 15.R₉₃ and R₉₄ are preferably hydrogen.

Specific phosphate esters of alkoxylated alcohol surfactants for use inthe herbicidal composition of the present invention include, forexample, EMPHOS CS-121, EMPHOS PS-400, and WITCONATE D-51-29, availablefrom Witco Corp. Other examples are indicated in Table A below for thePhospholan produces (available from Akzo Nobel) wherein the surfactantsmay comprise a mixture of the monoester and diester forms and whereinR₉₄ is not present in the diester as indicated and “prop.” refers toproprietary and “NR” refers to not reported. In some embodiments, thephosphate esters of the general monoester structure (10a) and thegeneral diester structure (10b) are not alkoxylated, i.e., m is 0.Examples of commercial products include Phospholan PS-900 and Phospholan3EA.

TABLE A mono R₂₉/ and di Trade name R₉₁ R₉₂ R₉₄ m forms PHOSPHALAN nonylC₂ H 6 mono CS-131 phenol & di PHOSPHALAN nonyl C₂ H 6 high CS-1361phenol mono & di PHOSPHALAN nonyl C₂ H 10 mono CS-141 phenol & diPHOSPHALAN nonyl C₂ H 8 mono CS-147 phenol & di PHOSPHALAN prop. prop.prop. prop. mono KPE4 PHOSPHALAN tridecyl C₂ H NR NR PS-131 PHOSPHALANdecyl/ C₂ H 30 mono PS-220 tetradecyl & di PHOSPHALAN dodecyl/ C₂ H 3mono PS-222 pentadecyl & di PHOSPHALAN decyl/ C₂ H 7 mono PS-236 dodecyl& di PHOSPHALAN tridecyl — H — mono PS-900 alcohol & di PHOSPHALANphenyl C₂ H 7 mono TS-230 & di PHOSPHALAN triethano- — H — mono 3EAlamine amine

Alkyl polysaccharide surfactants for use in the herbicidal compositionsof the present invention have the general structure (11):

R₁₀₁—O—(sug)_(u)  (11)

wherein R₁₀₁ is a straight or branched chain substituted orunsubstituted hydrocarbyl selected from alkyl, alkenyl, alkylphenyl,alkenylphenyl having from about 4 to about 22 carbon atoms, wherein sugand u are as defined above. In various particular embodiments thepolysaccharide surfactant may be an alkyl polyglucoside of formula (11)wherein: R₁₀₁ is a branched or straight chain alkyl group preferablyhaving from 4 to 22 carbon atoms, more preferably from 8 to 18 carbonatoms, or a mixture of alkyl groups having an average value within thegiven range; sug is a glucose residue; and u is between 1 and about 5,and more preferably between 1 and about 3.

Examples of surfactants of formula (11) are known in the art.Representative surfactants are presented in Table B below wherein foreach surfactant sug is a glucose residue.

TABLE B Trade name R₁₀₁ u APG 225 C₈₋₁₂ alkyl 1.7 APG 325 C₉₋₁₁ alkyl1.5 APG 425 C₈₋₁₆ alkyl 1.6 APG 625 C₁₂₋₁₆ alkyl 1.6 GLUCOPON 600 C₁₂₋₁₆alkyl 1.4 PLANTAREN 600 C₁₂₋₁₄ alkyl 1.3 PLANTAREN 1200 C₁₂₋₁₆ alkyl 1.4PLANTAREN 1300 C₁₂₋₁₆ alkyl 1.6 PLANTAREN 2000 C₈₋₁₆ alkyl 1.4 AGRIMULPG 2076 C₈₋₁₀ alkyl 1.5 (synonymous with AGNIQUE PG 8105) AGRIMUL PG2067 C₈₋₁₀ alkyl 1.7 (synonymous with AGNIQUE PG 8107) AGRIMUL PG 2072C₈₋₁₆ alkyl 1.6 (synonymous with AGNIQUE PG 816) AGRIMUL PG 2069 C₉₋₁₁alkyl 1.6 (synonymous with AGNIQUE PG 9116) AGRIMUL PG 2062 C₁₂₋₁₆ alkyl1.4 (synonymous with AGNIQUE PG 264) AGRIMUL PG 2065 C₁₂₋₁₆ alkyl 1.6(synonymous with AGNIQUE PG 266) BEROL AG6202 2-ethyl-1-hexyl

Alkoxylated alcohol surfactants for use in the herbicidal compositionsof the present invention have the general structure (12):

R₁₁₁O —(R₁₁₂O)_(x)R₁₁₃  (12)

wherein R₁₁₁ is hydrocarbyl or substituted hydrocarbyl having from 1 toabout 30 carbon atoms, R₁₁₂ in each of the (R₁₁₂O)_(x) groups isindependently C₂-C₄ alkylene, R₁₁₃ is hydrogen, or a linear or branchedalkyl group having from 1 to about 4 carbon atoms, and x is an averagenumber from 1 to about 60. In this context, preferred R₁₁₁ hydrocarbylgroups are linear or branched alkyl, linear or branched alkenyl, linearor branched alkynyl, aryl, or aralkyl groups. Preferably, R₁₁₁ is alinear or branched alkyl or linear or branched alkenyl group having fromabout 8 to about 30 carbon atoms, R₁₁₂ in each of the (R₁₁₂O)_(x) groupsis independently C₂-C₄ alkylene, R₁₁₃ is hydrogen, methyl or ethyl, andx is an average number from about 5 to about 50. More preferably, R₁₁₁is a linear or branched alkyl group having from about 8 to about 25carbon atoms, R₁₁₂ in each of the (R₁₁₂O)_(x) groups is independentlyethylene or propylene, R₁₁₃ is hydrogen or methyl, and x is an averagenumber from about 8 to about 40. Even more preferably, R₁₁₁ is a linearor branched alkyl group having from about 12 to about 22 carbon atoms,R₁₁₂ in each of the (R₁₁₂O)_(x) groups is independently ethylene orpropylene, R₁₁₃ is hydrogen or methyl, and x is an average number fromabout 8 to about 30. Preferred commercially available alkoxylatedalcohols include: EMULGIN L, PROCOL LA-15 (from Protameen); BRIJ 35,BRIJ 56, BRIJ 76, BRIJ 78, BRIJ 97, BRIJ 98 and TERGITOL XD (from SigmaChemical Co.); NEODOL 25-12 and NEODOL 45-13 (from Shell); HETOXOLCA-10, HETOXOL CA-20, HETOXOL CS-9, HETOXOL CS-15, HETOXOL CS-20,HETOXOL CS-25, HETOXOL CS-30, PLURAFAC A38 and PLURAFAC LF700 (fromBASF); ST-8303 (from Cognis); AROSURF 66 E10 and AROSURF 66 E20 (fromWitco/Crompton); ethoxylated (9.4 EO) tallow, propoxylated (4.4 EO)tallow and alkoxylated (5-16 EO and 2-5 PO) tallow (fromWitco/Crompton). Also preferred are; SURFONIC NP95 of Huntsman (apolyoxyethylene (9.5) nonylphenol); TERGITOL series from Dow andcommercially available from Sigma-Aldrich Co. (Saint Louis, Mo.),including TERGITOL-15-S-5, TERGITOL-15-S-9, TERGITOL-15-S-12 andTERGITOL-15-5-15 (made from secondary, linear C₁₁ to C₁₅ alcohols withan average of 5 moles, 9 moles, 12.3 moles and 15.5 moles ofethoxylation, respectively); the SURFONIC LF-X series from HuntsmanChemical Co. (Salt Lake City, Utah), including L12-7 and L12-8 (madefrom linear C₁₀ to C₁₂ alcohols with an average of 7 moles and 8 moles,respectively, of ethoxylation), L24-7, L24-9 and L24-12 (made fromlinear C₁₂ to C₁₄ alcohols with an average of 7 moles, 9 moles and 12moles of ethoxylation, respectively), L68-20 (made from primary, linearC₁₆₋₁₈ alcohols with an average of 20 moles of ethoxylation) and L26-6.5(made from linear C₁₂ to C₁₆ alcohols with an average of 6.5 moles ofethoxylation); and Ethylan 68-30 (C₁₆₋₁₈ with an average of 20 moles ofethoxylation) available from Akzo Nobel.

Amidoalkylamine surfactants for use in the herbicidal compositions ofthe present invention have the general structure (13):

wherein R₁₂₁ is a hydrocarbyl or substituted hydrocarbyl having from 1to about 22 carbon atoms, R₁₂₂ and R₁₂₃ are each independentlyhydrocarbyl or substituted hydrocarbyl having from 1 to about 6 carbonatoms and R₁₂₄ is hydrocarbylene or substituted hydrocarbylene havingfrom 1 to about 6 carbon atoms.

R₁₂₁ is preferably an alkyl or substituted alkyl having an average valueof carbon atoms between about 4 to about 20 carbon atoms, preferably anaverage value between about 4 and about 18 carbon atoms, more preferablyan average value from about 4 to about 12 carbon atoms, more preferablyan average value from about 5 to about 12 carbon atoms, even morepreferably an average value from about 6 to about 12 carbon atoms, andstill more preferably an average value from about 6 to about 10 carbonatoms. The R₁₂₁ alkyl group may be derived from a variety of sourcesthat provide alkyl groups having from about 4 to about 18 carbon atoms,for example, the source may be butyric acid, valeric acid, caprylicacid, capric acid, coco (comprising mainly lauric acid), myristic acid(from, e.g., palm oil), soy (comprising mainly linoleic acid, oleicacid, and palmitic acid), or tallow (comprising mainly palmitic acid,oleic acid, and stearic acid). In some embodiments, the amidoalkylaminesurfactant component may comprise a blend of amidoalkylamines havingalkyl chains of various lengths from about 5 carbon atoms to about 12carbon atoms. For example, depending upon the source of the R₁₂₁ alkylgroup, an amidoalkylamine surfactant component may comprise a blend ofsurfactants having R₁₂₁ groups that are 5 carbon atoms in length, 6carbon atoms in length, 7 carbon atoms in length, 8 carbon atoms inlength, 9 carbon atoms in length, 10 carbon atoms in length, 11 carbonatoms in length, and 12 carbon atoms in length, longer carbon chains,and combinations thereof. In other embodiments, the amidoalkylaminesurfactant component may comprise a blend of surfactants having R₁₂₁groups that are 5 carbon atoms in length, 6 carbon atoms in length, 7carbon atoms in length, and 8 carbon atoms in length. In somealternative embodiments, the amidoalkylamine surfactant component maycomprise a blend of surfactants having R₁ groups that are 6 carbon atomsin length, 7 carbon atoms in length, 8 carbon atoms in length, 9 carbonatoms in length, and 10 carbon atoms in length. In other embodiments,the amidoalkylamine surfactant component may comprise a blend ofsurfactants having R₁₂₁ groups that are 8 carbon atoms in length, 9carbon atoms in length, 10 carbon atoms in length, 11 carbon atoms inlength, and 12 carbon atoms in length.

R₁₂₂ and R₁₂₃ are independently preferably an alkyl or substituted alkylhaving from 1 to about 4 carbon atoms. R₁₂₂ and R₁₂₃ are most preferablyindependently an alkyl having from 1 to about 4 carbon atoms, and mostpreferably methyl. R₁₂₄ is preferably an alkylene or substitutedalkylene having from 1 to about 4 carbon atoms. R₁₂₄ is most preferablyan alkylene having from 1 to about 4 carbon atoms, and most preferablyn-propylene. When R₁₂₄ is n-propylene, the amidoalkylamine surfactantsare termed amidopropylamine (APA) surfactants.

In one preferred amidoalkylamine surfactant, R₁₂₁ is C₆₋₁₀, i.e., analkyl group having 6 carbon atoms, 7 carbon atoms, 8 carbon atoms, 9carbon atoms, 10 carbon atoms, or a blend of any of these, i.e., fromabout 6 carbon atoms to about 10 carbon atoms; R₁₂₂ and R₁₂₃ are eachmethyl; and R₁₂₄ is n-propylene (i.e., C₆₋₁₀ amidopropyl dimethylamine).

Examples of APA surfactants include Armeen APA 2 (where R₁₂₁ is C₂ andR₁₂₂ and R₁₂₃ are each hydrogen) , Armeen APA 6 (where R₁₂₁ is C₆ andR₁₂₂ and R₁₂₃ are each methyl) , Armeen APA 8, 10 (where R₁₂₁ is C₈₋₁₀and R₁₂₂ and R₁₂₃ are each methyl) , Armeen APA 12 (where R₁₂₁ is C₁₂and R₁₂₂ and R₁₂₃ are each methyl) , ACAR 7051 (where R₁₂₁ is C₅₋₉ andR₁₂₂ and R₁₂₃ are each methyl) , ACAR 7059 (where R₁₂₁ is 2-ethyl hexyland R₁₂₂ and R₁₂₃ are each methyl) and Adsee C80W (where R₁₂₁ is Cocoand R₁₂₂ and R₁₂₃ are each methyl).

The herbicidal compositions may further comprise other conventionaladjuvants such as solvents, emulsifiers, chelating agents, emollients,permeation enhancers, antioxidants, lubricants, pH adjusters, adjuvants,dyes, conventional drift control agents, safeners, thickeners, flowenhancers, antifoaming agents, freeze protectants and/or UV protectants.

Suitable drift control agents are known to those skilled in the art andinclude the commercial products GARDIAN, GARDIAN PLUS, DRI-GARD, PRO-ONEXL, ARRAY, COMPADRE, IN-PLACE, BRONC Max EDT, EDT CONCENTRATE, COVERAGEand BRONC PLUS DRY EDT. Safeners are likewise known to those skilled inthe art and include isoxadifen, benoxacor and dichlormid known to thoseskilled in the art. These other additives or ingredients may beintroduced into the compositions of the present invention to provide orimprove certain desired properties or characteristics of the formulatedproduct.

Generally, the aqueous gel compositions of the instant invention areformed by mechanically admixing a solution comprising one or moreherbicides or mixture of herbicides and a soluble gel forming agent orgel forming agent solution. As described, above the total herbicideconcentration is from about 1 to about 50 g a.e./L (0.1 to 5 wt %) andthe gel forming agent concentration is likewise from about 0.1 to about5 wt %. Accordingly, the weight ratio range of total herbicideconcentration to gel forming agent is from about 50:1 to about 1:50, forexample 1:1, 1:2, 1:5, 1:10, 1:25, 1:50, 50:1, 25:1, 10:1, 5:1, 2:1 andranges thereof.

The pseudoplastic characteristics of the gel compositions provide foradvantages in processing. The herbicides and gel forming agents can becombined with agitation, having sufficient shear to cause a compositionviscosity decrease. The resulting thin composition increases mixingefficiency minimizes power consumption and heat generation and thusmaximizes processing efficiency.

In some embodiments of the present invention, polyacrylic acid or aCARBOPOL-derived gel forming agents or other pH-responsive gel formingagents are advantageously used because at an acidic pH (about 5 orbelow) these gel forming agents do not appreciably thicken the solution.Therefore, herbicides such as glyphosate mono salts, having a pH of lessthan about 5, can be easily admixed with the gel forming agent. In someother embodiments of the present invention, a gellan gum gel formingagent is used as the gel forming agent because it does not appreciablythicken in solution at a pH of about 3.5 or below. Thereafter a gel canbe formed by pH adjustment above about 5 (or above about 3.5 for gellangum). Alternatively, a solution of basic herbicide can be adjusted to apH of less than about 5 (or less than about 3.5 for gellan gum) followedby admixing with the polyacrylic acid or CARBOPOL gel forming agent (orgellan gum). The pH of the mixture can then be adjusted above 5 (or 3.5)to form the gel.

Suitable bases for neutralizing polyacrylic acid polymers and otherpH-responsive gel forming agents include, for example and withoutlimitation, sodium hydroxide, potassium hydroxide, ammonia, and aminessuch as monoethanolamine, diethanolamine and triethanolamine.

The present invention is further directed to methods of confinedapplication of agrochemical gels to unwanted plants such as weeds and/orcertain crop plants such as volunteer crops that germinate and grow froma seed remaining after the harvest of a prior crop plant. As explainedabove, in some embodiments, the gel compositions of the presentinvention can be directly applied to the foliage or exposed areas ofindividual plants such as by spraying from hand-held sprayers (e.g. aspray bottle), canisters or tanks, or by applicators such as brushes,rollers or sponges. In other embodiments, the gels can broadcast appliedto larger areas containing unwanted plant growth my methods known in theart such as by applying to a foliage canopy by spraying. The sheargenerated during pumping, brushing, shaking, stirring or transferthrough a spray nozzle reduces gel viscosity to allow the composition toflow and thereby facilitate the efficient application or dispersal ofthe gel composition.

In more detail, in accordance with the present invention, the aqueousgel compositions may be directly applied to plant foliage by any ofvarious means known in the art including, but not limited to, (i)application to a foliage canopy using aerial spraying systems,farm-scale ground based spraying application such as from a truck ortrailer mounted system, or hand-held spraying methods such as from acanister or tank or (ii) targeted application to plant foliage ofindividual plants by using hand-held sprayers, brushes, rollers,sponges, wick applicators. The gel compositions can be optionallyapplied to non-foliar plant tissue by methods including (i) cut stumpapplication wherein the plant is cut off completely at its base leavinga stump and root system, and the gel composition is applied onto the cutsurface of the stump, (ii) cut and swab application wherein plants suchas vines or multi-stemmed shrubs are cut completely through and the gelcomposition is applied to the cut surface emerging from the ground,(iii) stem scraping wherein a thin layer of bark is scraped or otherwiseremoved from a section of a stem and the gel composition is applied tothe exposed plant tissue or (iv) hack and squirt application wherein aring of bark is removed from the trunk of the plant, typically usingdownward cuts, leaving a reservoir or “cup” to hold appliedagrochemicals into which the gel composition is then applied and therebyexposed plant tissue in the cut area.

After the gel composition is applied to the plant (such as ontofoliage), where low or zero shear conditions are present, the viscosityincreases to about the viscosity observed under static conditions. Theretention time on the plant is significantly enhanced due to therheological properties of the gel as previously described. For example,as compared to broadcast applied herbicide or tank mixed herbicidesknown in the art, the substantially greater stationary viscosity andelastic nature of the gels of the present invention improves adhesionand retention time on the plant. In addition, the applied gelcompositions of the present invention resist drying and have an abilityto retain moisture content for significantly longer durations incomparison to broadcast applied herbicide or tank mixed herbicides ofthe prior art.

Unwanted plants within the scope of the present inventions include,without limitation, weeds and/or volunteer crop plants. Volunteer cropplants of the present invention include hybrids, inbreds, and transgenicor genetically modified plants such as, vegetable crops, grain crops,flowers, root crops and sod. Examples of volunteer crop plants includecorn, cotton and soybeans. Weeds include velvetleaf (Abutilontheophrasti), pigweed (Amaranthus spp.), buttonweed (Borreria spp.),indian mustard (Brassica spp.), commelina (Commelina spp.), filaree(Erodium spp.), sunflower (Helianthus morningglory (Ipomoea spp.),kochia (Kochia scoparia), mallow (Malva spp.), wild buckwheat, smartweed(Polygonum spp.), purslane (Portulaca spp.), russian thistle (Salsolasida (Sida spp.), wild mustard (Sinapis arvensis), cocklebur (Xanthiumspp.), wild oat (Avena fatua), carpetgrass (Axonopus spp.), downy brome(Bromus tectorum), crabgrass (Digitaria barnyardgrass (Echinochloacrus-galli), goosegrass (Eleusine indica), annual ryegrass (Loliummultiflorum), ottochloa (Ottochloa nodosa), bahiagrass (Paspalumnotatum), canarygrass (Phalaris foxtail (Setaria spp.), mugwort(Artemisia spp.), milkweed (Asclepias spp.), canada thistle (Cirsiumarvense), field bindweed (Convolvulus arvensis), kudzu (Pueraria spp.),brachiaria (Brachiaria bermudagrass (Cynodon dactylon), yellow nutsedge(Cyperus esculentus), purple nutsedge (C. rotundus), quackgrass (Elymusrepens), lalang (Imperata cylindrica), perennial ryegrass (Loliumperenne), guineagrass (Panicum maximum), dallisgrass (Paspalumdilatatum), reed (Phragmites spp.),johnsongrass (Sorghum halepense),cattail (Typha spp.), horsetail (Equisetum spp.), bracken (Pteridiumaquilinum), blackberry (Rubus spp.), and gorse (Ulex europaeus).

In some embodiments of the present invention, the target weeds,volunteer crop plants and/or desirable crop plants can have one or moreherbicide tolerant traits. For example, the plants may have tolerance toglyphosate, auxins (e.g., 2,4-D, dicamba, etc.), glufosinate,acetolactate synthase inhibitor herbicides or acetyl CoA carboxylaseinhibitors (e.g., sethoxydim), etc.). In other embodiments, the cropplants comprise stacked traits such as auxin and glyphosate tolerance.In other embodiments, the plants can additionally include otherherbicide, insect and disease tolerance traits, as well as combinationsof those traits.

In some methods, glyphosate gel compositions of the present inventionare applied to the foliage canopy of weeds and/or volunteer crop plants(collectively termed hereafter “unwanted plants”) wherein the unwantedplants are growing in and/or adjacent to a field of desirable cropplants having a glyphosate-tolerant trait.

In some other methods, the water-soluble herbicide component of the gelcompositions comprises glyphosate and glufosinate or glufosinate-P andthe desirable crop plants have glyphosate-tolerant andglufosinate-tolerant traits. Such methods are useful for controllingunwanted plants having glyphosate or glufosinate tolerance.

In some other methods, the water-soluble herbicide component of the gelcompositions comprises glyphosate and at least one auxin herbicide, andthe desirable crop plants have glyphosate-tolerant and auxin-toleranttraits. Such methods are useful for controlling unwanted plants havingglyphosate or auxin tolerance.

In some other methods, the water-soluble herbicide component of the gelcompositions comprises glyphosate and at least one ALS inhibitorherbicide (or racemic mixtures or resolved isomers thereof, and/or saltsor esters thereof), and the desirable crop plants haveglyphosate-tolerant and ALS inhibitor-tolerant traits. Such methods areuseful for controlling unwanted plants having glyphosate or ALSinhibitor tolerance.

In some other methods, the water-soluble herbicide component of the gelcompositions comprises glyphosate, at least one auxin herbicide, andglufosinate or glufosinate-P (or salts or esters thereof), and thedesirable crop plants have glyphosate, auxin and glufosinate-toleranttraits. Such methods are useful for controlling unwanted plants havingglyphosate, glufosinate or auxin tolerance, or tolerance to herbicidesfrom two of those classes, as well combinations of such unwanted plantsspecies. For instance, the method would be useful for the control of afirst unwanted plant species having glyphosate tolerance, and a secondunwanted plant species having tolerance to auxins and glufosinatewherein both unwanted plant species are present in a field of the cropplants.

In some other methods, the water-soluble herbicide component of the gelcompositions comprises glyphosate, at least one auxin herbicide and atleast one ALS inhibitor herbicide (or racemic mixtures or resolvedisomers thereof, and/or salts or esters thereof), and the desirable cropplants have glyphosate, auxin and ALS inhibitor-tolerant traits. Suchmethods are useful for controlling unwanted plants having glyphosate,auxin or ALS inhibitor-tolerance, or tolerance to herbicides from two ofthose classes, as well combinations of such unwanted plants species. Forinstance, the method would be useful for the control of a first unwantedplant species having glyphosate tolerance, and a second unwanted plantspecies having tolerance to auxins and ALS inhibitors wherein bothunwanted plant species are present in a field of the crop plants.

In some other methods, the water-soluble herbicide component of the gelcompositions comprises glyphosate, at least one ALS inhibitor herbicideand glufosinate or glufosinate-P (or racemic mixtures or resolvedisomers thereof, and/or salts or esters thereof), and the desirable cropplants have glyphosate, ALS inhibitor and glufosinate-tolerant traits.Such methods are useful for controlling unwanted plants havingglyphosate, ALS inhibitor or glufosinate-tolerance, or tolerance to twoof those herbicides, as well combinations of such unwanted plantsspecies. For instance, the method would be useful for the control of afirst unwanted plant species having glyphosate tolerance, and a secondunwanted plant species having tolerance to ALS inhibitors andglufosinate wherein both unwanted plant species are present in a fieldof the crop plants.

In yet some other methods, the water-soluble herbicide component of thegel compositions comprises glyphosate, at least one auxin herbicide, atleast one ALS inhibitor herbicide and glufosinate or glufosinate-P (orracemic mixtures or resolved isomers thereof, and/or salts or estersthereof), and the desirable crop plants have glyphosate, auxin, ALSinhibitor and glufosinate-tolerant traits. Such methods are useful forcontrolling unwanted plants having glyphosate, auxin, ALS inhibitor orglufosinate-tolerance, or tolerance to up to three of those herbicides,as well combinations of such unwanted plants species. For instance, themethod would be useful for the control of a first unwanted plant specieshaving glyphosate tolerance, and a second unwanted plant species havingtolerance to ALS inhibitors, glufosinate and auxins wherein bothunwanted plant species are present in a field of the crop plants.

In embodiments of the present invention wherein the crop plant has anauxin-tolerant trait, when the auxin herbicide is 2,4-D, the crop plantis tolerant to 2,4-D; when the auxin herbicide is aminopyralid, the cropplant is tolerant to aminopyralid; when the auxin herbicide isclopyralid, the crop plant is tolerant to clopyralid; when the auxinherbicide is dicamba, the crop plant is tolerant to dicamba; when theauxin herbicide is fluroxypyr, the crop plant is tolerant to fluroxypyr;when the auxin herbicide is mecoprop or mecoprop-P, the crop plant istolerant to mecoprop; when the auxin herbicide is picloram, the cropplant is tolerant to picloram; and/or when the auxin herbicide istriclopyr, the crop plant is tolerant to triclopyr. In some embodimentsthe auxin herbicide is 2,4-D or dicamba.

In embodiments of the present invention wherein the crop plant has anALS or AHAS tolerant trait, when the ALS or AHAS inhibitor herbicide isimazamethabenz-m, the crop plant is tolerant to imazamethabenz-m; whenthe ALS or AHAS inhibitor herbicide is imazamox, the crop plant istolerant to imazamox; when the ALS or AHAS inhibitor herbicide isimazapic, the crop plant is tolerant to imazapic; when the ALS or AHASinhibitor herbicide is imazapyr, the crop plant is tolerant to imazapyr;when the ALS or AHAS inhibitor herbicide is imazaquin, the crop plant istolerant to imazaquin; and/or when the ALS or AHAS inhibitor herbicideis imazethapyr, the crop plant is tolerant to imazethapyr.

The methods of the present invention enable from about 10 to about 20,from about 10 to about 30, from about 10 to about 40 or from about 10 toabout 50 percent by weight of the amount of agrochemical applied to theplant foliage to be transferred into the plant. This represents asignificant advance over the prior art where typically only about 10percent of an applied agrochemical is transferred into the target plant.

In some of the inventive methods, at least 60%, 65%, 70%, 75%, 80%, oreven at least 85%, or even at least 90% control of the unwanted plantsis achieved. Although it is generally preferable from a commercialviewpoint that 80-85% or more of the plants be destroyed, commerciallysignificant plant control can occur at much lower levels, particularlywith some very noxious, herbicide-resistant plants. “Plant control,” asused herein, refers to any observable measure of control of plantgrowth, which can include one or more of the actions of (1) killing, (2)inhibiting growth, reproduction or proliferation, and (3) removing,destroying, or otherwise diminishing the occurrence and activity ofplants. Plant control can be measured by any of the various methodsknown in the art. For example, plant control can be determined as apercentage as compared to untreated plants following a standardprocedure wherein a visual assessment of plant mortality and growthreduction is made by one skilled in the art specially trained to makesuch assessments. In another control measurement method, control isdefined as a mean plant weight reduction percentage between treated anduntreated plants.

In some of the inventive methods, injury to desirable crop plants isless than 20%, 15%, 10% or even less than about 5%. Damage to desirablecrops can be measured by any means known in the art, such as thosedescribe above for plant control determination.

In some embodiments of the present invention, at least 80% control ofthe unwanted plants is achieved no greater than 5, 10, 15, 20, 25 or 30days after application of the compositions to the unwanted plants. Insome embodiments, visual indications of plant injury are observablewithin one day of treatment. In some other embodiments, desirable cropplant injury is less than 20% no greater than 1, 5, 10, 15, 20, 25 oreven 30 days after application of the compositions to the unwantedplants. In yet some other embodiments, at least 80% control of theunwanted plants is achieved and desirable crop plant injury is less than20%, preferably not greater than 30 days after application of thecompositions.

Having described the invention in detail, it will be apparent thatmodifications and variations are possible without departing from thescope of the invention defined in the appended claims.

EXAMPLES

The following non-limiting examples are provided to further illustratethe present invention.

The components in Table I below are used in the Examples.

TABLE I Component Description Gel1 Carbopol Aqua 30, 30% polymer Gel2Carbopol 1342 Gel3 Carbopol Ultrez 20 Gel4 Carbopol EZ3 Gel5 2% CMC-9000Gel6 Kelzan ASX Gel7 Kelzan ASX T Surf1 70% tallowamine 15 EOsurfactant: PEG:ethylene glycol Surf2 Tomadol 1-7 Surf3 Witco C-6150ether amine ethoxylate Surf4 Surfonic AGM 550 surfactant Surf5 55%tallowamine 10EO (Witcamine TAM- 105) : 45% cocoamine 2EO (Witcamine302) Dfm1 SAG 1671 silicone antifoam emulsion Dfm2 SAG 10 siliconeantifoam emulsion Dfm3 SAG 1572 silicone antifoam emulsion

The composition of the experimental glyphosate aqueous gel formulationsis indicated in Table II, III, and IV below where the concentrations arereported on a weight percent acid equivalent basis unless indicatedotherwise. In Table III, “RU SC” refers to ROUNDUP SUPER CONCENTRATE(“RU SC”) available from Monsanto company and that contains 445 gramsa.e. per liter of the isopropylamine salt of glyphosate and surfactant.The formulations were typically prepared by first making an aqueoussolution of the glyphosate salt followed by addition of the antifoamagent (if present), the surfactant (if present), the gelling orthickening agent and finally the base. Alternatively, the order ofaddition could be as follows, dilution of the glyphosate salt intowater, addition of the base followed by addition of the gel premix withadjustment of pH to near neutral if needed by further addition of base.In Tables II-IV, “IPA-gly” refers to isopropylamine glyphosate, “surf.”Refers to surfactant, “gly salt” refers to glyphosate salt, and wt % gelrefers to weight percent gel on an active basis.

TABLE II Formulation M257 M258 M261 M262 817-3 IPA-gly (wt % a.e.) 0.740.74 0.74 0.74 0.74 Gel Gel1 Gel1 Gel1 Gel1 Gel2 wt % gel 3.0 3.0 3.03.0 0.75 surf. Surf1 none none Surf1 none wt % surf. 0.25 0 0 0.25 0Pelargonic acid wt % 0 0 2.00 2.00 0 Base KOH KOH KOH KOH KOH pH 7 7 7.57.5 7 Formulation 821-4 822-5 827-2 469 IPA-gly (wt % a.e.) 0.74 0.740.74 0.74 Gel Gel2 Gel5 Gel5 Gel1 wt % gel 0.75 1.3 1.3 3.0 surf. Surf1none Surf1 none wt % surf. 0.25 0 0.25 0 Pelargonic acid wt % 0 0 0 0Base KOH KOH KOH KOH pH 7 nd Nd 6-6.5 nd refers to “not determined”

TABLE III Formulation N893B N893C N894A N894B RU SC IPA-gly 0.07 0.190.37 0.56 50.3 wt % a.e. Gel Gel1 Gel1 Gel1 Gel1 none wt % gel 3.0 3.03.0 3.0 0 Base KOH KOH KOH KOH none pH 7 7 7 7

Except for M737 all formulations in Table IV below also contain 0.1 gProxel GXL and 0.1 g antifoam agent Sag 1572 per 100 g solution.Additionally, formulations N485-6, N485-7, N485-8 and M737 contain 1%pelargonic acid.

TABLE IV Gly wt % Comp2 Form. Salt a.e. Gel1 Base Comp2 amt(g) pH N482-5IPA 0.51 3.0 KOH None 0 7.0 N482-4 IPA 0.74 3.0 KOH None 0 7.2 N482-1IPA 1.00 3.0 KOH None 0 6.9 N485-1 K 0.51 3.0 KOH none 0 7.1 N479-2 K0.75 3.0 KOH none 0 6.9 N479-3 K 1.00 3.0 KOH none 0 6.9 N485-4 K 0.513.0 KOH SURF1 0.2 7.0 N485-3 K 0.75 3.0 KOH SURF1 0.2 7.4 N485-2 K 1.03.0 KOH SURF1 0.2 7.2 N485-5 K 0175 3.0 KOH SURF1 0.4 7.3 N485-6 K 0.753.0 KOH None 0 7.5 N485-7 K 0.75 3.0 KOH SURF1 0.2 6.9 N485-8 K 0.75 3.0KOH AMS 1.0 6.8 N482-2 IPA 1.0 3.0 TEA none 0 6.9 N482-3 IPA 1.0 3.0NaOH None 0 7.4 M737 IPA 0.72 0 none SURF1 0.15 nd

Example 1—Rheology Experiments

The rheology properties for formulation M258 from Table II, additionallycontaining 0.01% antifoam agent Dfm3 and 0.1% Proxel GXL biocide, weremeasured. Viscosity as a function of shear rate was measured using a TArheometer with a 60 mm 2° acrylic cone and plate at 20° C. with anoscillating frequency of 100 rad/s. The results are reported in Table 1aand are depicted in FIG. 1 .

TABLE 1a shear rate Viscosity Shear Viscosity (s − 1) (Pa · s) (RPM)(cps) 1 19.47 0.02 19470 11 2.77 0.18 2769 21 1.67 0.35 1668 31 1.250.52 1245 42 1.02 0.70 1016 52 0.87 0.87 869 62 0.77 1.03 768 72 0.691.20 693 82 0.64 1.37 635 92 0.59 1.53 589 103 0.55 1.72 550 113 0.521.88 518 123 0.49 2.05 491 133 0.47 2.22 468 143 0.45 2.38 448 153 0.432.55 430 163 0.41 2.72 414 174 0.40 2.90 400 184 0.39 3.07 387 194 0.383.23 376 204 0.37 3.40 365 214 0.36 3.57 356 224 0.35 3.73 347 235 0.343.92 340 245 0.33 4.08 331 255 0.32 4.25 324 265 0.32 4.42 318 275 0.314.58 312 285 0.31 4.75 306 295 0.30 4.92 301 306 0.30 5.10 296 316 0.295.27 291 326 0.29 5.43 286 336 0.28 5.60 282 346 0.28 5.77 278 356 0.275.93 274 367 0.27 6.12 271 377 0.27 6.28 268 387 0.26 6.45 264 397 0.266.62 261 407 0.26 6.78 258 417 0.26 6.95 255 427 0.25 7.12 253 438 0.257.30 250 448 0.25 7.47 248 458 0.25 7.63 245 468 0.24 7.80 243 478 0.247.97 241 488 0.24 8.13 239 499 0.24 8.32 237 509 0.24 8.48 235 519 0.238.65 233 529 0.23 8.82 232 539 0.23 8.98 230 549 0.23 9.15 229 559 0.239.32 228 570 0.23 9.50 226 580 0.22 9.67 225 590 0.22 9.83 224 600 0.2210.00 222

Oscillation frequency sweep rheometric measurements for M258 formulationat 0.2 Pa and 1 Pa were measured on a TA rheometer with a 60 mm 2°acrylic cone and plate at 20° C. The results 0.2 Pa results are shown inTable 1b and depicted in FIGS. 2 and 3 . The 1 Pa results are shown inTable 1c and depicted in FIG. 4 . In Tables 1b and 1c and FIGS. 3 and 5, G′ is the elastic modulus, which is a measure of the ability of thegel to store energy and loosely corresponds to solid-like behavior, andG″ is the viscous modulus, which is a measure of the tendency of the gelto dissipate energy that is transferred to the gel. This modulus isloosely correlated with liquid-like behavior. Tan (delta) is G″/G′.

TABLE 1b Frequency Sweep at 0.2 Pa stress Frequency, G′ G″ Viscosity tanrad/s (Pa) (Pa) Pa · s (delta) 0.1 68.4 11.51 115.1 0.168 0.129 70.410.04 79.79 0.143 0.159 71.8 9.26 58.4 0.129 0.2 73.1 8.73 43.77 0.1190.251 74.3 8.68 34.56 0.117 0.316 75.4 8.32 26.32 0.110 0.398 76.9 8.421.1 0.109 0.501 78 8.48 16.93 0.109 0.631 79.2 8.58 13.6 0.108 0.79480.6 8.18 10.3 0.102 1 81.6 8.2 8.2 0.100 1.259 82.6 8.43 6.7 0.1021.585 84 8.47 5.34 0.101 1.995 85.2 8.61 4.31 0.101 2.512 86 9.05 3.610.105 3.162 87.1 9.31 2.94 0.107 3.981 88.3 9.42 2.37 0.107 5.012 89.810.08 2.01 0.112 6.31 90.9 10.53 1.67 0.116 7.943 92.3 11.23 1.41 0.12210 93.5 11.8 1.18 0.126 12.59 95.1 12.94 1.03 0.136 15.85 96.6 13.710.86 0.142 19.95 98.5 15.33 0.77 0.156 25.12 100.4 16.73 0.67 0.16731.62 102.2 18.27 0.58 0.179 39.81 104.9 20.44 0.51 0.195 50.12 107.322.18 0.44 0.207 63.1 110.1 24.94 0.4 0.227 79.43 113.4 27.54 0.35 0.243100 116.8 30.55 0.31 0.262 125.9 120.5 33.95 0.27 0.282 158.5 124.937.68 0.24 0.302 250.8 140.4 38.43 0.15 0.274 316.2 176.9 17.99 0.060.102 398.1 155.7 22.14 0.06 0.142 500.7 160.7 67.55 0.13 0.420 601.3192.5 52.42 0.09 0.272

TABLE 1c Frequency Sweep at 1 Pa stress Frequency, Viscosity, tan rad/sG′ Pa G″ Pa Pa · s delta 0.1 73.2 8.65 86.48 0.118 0.129 74.6 8.37 66.490.112 0.159 76 8.18 51.58 0.108 0.2 77.3 8.08 40.49 0.104 0.251 78.68.02 31.9 0.102 0.316 79.8 7.94 25.11 0.1 0.398 81 7.85 19.7 0.1 0.50182.2 7.88 15.71 0.096 0.631 83.4 7.88 12.49 0.095 0.794 84.5 7.82 9.850.093 1 85.6 7.84 7.84 0.092 1.259 86.7 7.9 6.27 0.091 1.585 87.9 7.975.03 0.091 1.995 88.8 8.08 4.05 0.091 2.512 90.1 8.29 3.3 0.092 3.16291.2 9.11 2.88 0.1 3.981 92.4 9.48 2.38 0.103 5.012 93.4 9.95 1.99 0.1076.31 94.7 10.6 1.68 0.112 7.943 95.9 11.3 1.42 0.118 10 97.4 12.14 1.240.125 12.59 98.9 13.11 1.04 0.133 15.85 100.5 14.3 0.90 0.143 19.95102.2 15.58 0.78 0.152 25.12 104 17.12 0.68 0.165 31.62 105.9 18.8 0.590.178 39.81 108.1 20.7 0.52 0.191 50.12 110.3 22.8 0.46 0.207 63.1 112.625.19 0.4 0.224 79.43 115.1 27.82 0.35 0.242 100 117.4 30.37 0.30 0.259125.9 120.4 33.44 0.27 0.278 158.5 124.1 38.94 0.25 0.314 251.2 143.354.53 0.22 0.381 300 129.6 49.58 0.17 0.383

Tan delta measurements for Table II formulations 817-3, 821-4, 822-5,827-2 and 469 were measured using a TA rheometer with a 60 mm 2° acryliccone and plate at 20° C. at 1% strain. Results are provided in Table 1dand are depicted in FIG. 7 .

TABLE 1d Freq. Tan Delta (Hz) 817-3 821-4 822-5 827-2 469 1 0.07480.1884 1.015 1.054 0.116 1.259 0.0751 0.1934 0.9706 1.004 0.1184 1.5850.0766 0.1988 0.9284 0.9541 0.1212 1.995 0.0782 0.205 0.885 0.90450.1251 2.512 0.0811 0.2115 0.8504 0.8619 0.1308 3.163 0.084 0.21740.8183 0.8185 0.1366 3.982 0.0884 0.224 0.7922 0.7814 0.1444 5.0110.0932 0.2296 0.7696 0.7537 0.1538 6.311 0.09875 0.2358 0.7532 0.72280.1636 7.944 0.1067 0.2399 0.7444 0.71 0.1752 9.997 0.1149 0.2434 0.74630.6994 0.1886 12.59 0.1244 0.2445 0.7703 0.7024 0.2034

The formulations in Table 1e were prepared by the method used to preparethe Table II formulations. The viscosity of the Table 1e formulationswere measured on a Brookfield DV-II viscometer at 25° C. using thespindle as indicated with the results in cP reported in Table 1f and aredepicted in FIG. 8 .

TABLE 1e Carbopol 45% Proxel SAG Aqua 30 KOH GXL 1572 Form. (% by wt) (%by wt) (% by wt) (% by wt) pH M258-2 3.0 1.88 0.1 0.01 7 M258-3 2.5 1.750.1 0.01 7.5-8 M258-4 2.0 1.18 0.1 0.01 7 M258-5 1.5 1.10 0.1 0.01 7

Viscosity Tests on Brookfield DV-II Viscometer

TABLE 1f Spindle #3 #3 #3 #2 Form. M258-2 M258-3 M258-4 M258-5 0.3 RPM 17400 9250 6350 3510 0.6 RPM  9700 5130 3550 2040 1.5 RPM  4560 24401690 960  3 RPM 2640 1410 979 570  6 RPM 1540 843 585 340 12 RPM 783 503345 207 30 RPM 312 262 180 110 60 RPM 157 157 111 63

Yield point and viscosity data were measured for the formulations inTable IV that contained a gelling agent, a commercially available gelcomposition (Speed Stick Gel by Mennen, available fromColgate-Palmolive), and a formulation containing no glyphosate(identified as 3% carbopol gel). The formulations in Table 1g wereprepared by the method used to prepared the Table II formulations. Thevalues were determined using the TA rheometer with the cone and plategeometry and viscosity was measured as a function of shear rate. Theresulting curve was then fitted with Bingham rheological model, andyield point and viscosity were calculated based on these curves. In theBingham rheological model, a fluid is presumed not to flow until anapplied shear stress, T, exceeds a minimum value, τ₀. This minimum valueof shear stress is known as the “yield point” (YP). At stress levelsabove the YP, changes in shear stress become proportional to the changesin the shear rate. The proportionality constant is known as the plasticviscosity (PV), represented in the equation below as γ. The BinghamPlastic model can be represented by the following expression:

τ=τ₀+μ_(B)γ

wherein γ is the proportionality constant, also known as the plasticviscosity (PV) and μ_(B) is the constant Bingham viscosity. The data isprovided in Table 1g.

TABLE 1g Yield Pt Viscosity AE Sample (dyne/cm2) (poise) Loading N482-5255.3 99.5 0.51 N482-4 281.3 117.9 0.74 N482-1 231.9 106.3 1 N485-1 24090.12 0.51 N479-2 256.6 123.7 0.75 N479-3 195.6 108.5 1 N485-4 219.5176.8 0.51 N485-3 249.1 156.2 0.75 N485-2 185.7 150.5 1 N485-5 178.3131.7 0.75 N485-6 146 90.25 0.75 N485-7 167.2 88.17 0.75 N485-8 64.8755.4 0.75 Mennen gel 77 228.5 0 3% carbopol 175.9 116.9 0 gel N482-2 19295.87 1 N482-3 244.6 107 1

These data demonstrate that to be most useful, the gel must haverheological properties such that it is elastic in nature or have a valueof tan delta less than 1 (tan δ<1). This elastic nature is importantbecause with a high elasticity the gel will be retained on the leaf andnot spread and run off of the site where it is applied as a gel that ismore viscous than elastic in nature will do. The calculated yield pointsfor the gels in Table IV range from 176 to 281 dyne/cm² and support thelow run-off potential of the gel when applied to leaf surface.

Example 2

An experiment was performed to determine the efficacy of experimentalgel application mixtures relative to a comparative application mixturenot containing a gelling agent (M737). Formulations from Table IV wereapplied using a standard deodorant gel applicator used in personal careindustry to TAROF (flowering stage 6 in diameter), FESAR (tilleringstage 3-4 in tall), and PLAMA (4-6 in diameter) in field tests to assessweed control efficacy. Approximately 1.1 grams of each gel was appliedto each individual weed and spread over the entire leaf surface. Table2a indicates the estimated glyphosate application rate applied to eachplant on a g a.e./weed basis and a kg a.e./ha basis where “Trt.” refersto treatment number, “Form.” refers to formulation number, “TAROF”refers to common dandelion, “FESAR” refers to tall fescue and “PLAMA”refers to broadleaf plantain. The calculations were based on a TAROFarea of 182.5 cm², a FESAR area of 96.8 cm² and a PLAMA area of 81.3cm².

TABLE 2a glyphosate TAROF kg FESAR kg PLAMA kg Trt. Form. a.e./weeda.e/ha a.e/ha a.e/ha  1 N482-5 0.0056 3.06 5.80 6.89  2 N482-4 0.00814.43 8.38 9.96  3 N482-1 0.011 6.01 11.38 13.53  4 N485-1 0.0056 3.065.80 6.89  5 N479-2 0.0083 4.53 8.59 10.21  6 N479-3 0.011 6.01 11.3813.53  7 N485-4 0.0056 3.06 5.80 6.89  8 N485-3 0.0083 4.53 8.59 10.21 9 N485-2 0.011 6.01 11.38 13.53 10 N485-5 0.0083 4.53 8.59 10.21 11N485-6 0.0083 4.53 8.59 10.21 12 N485-7 0.0083 4.53 8.59 10.21 13 N485-80.0083 4.53 8.59 10.21 14 M737 0.0108 5.90 11.18 13.29

Injury ratings were taken at 1, 3, 7 and 15 days after treatment (DAT)and the data is reported in Tables 2b, 2c, 2d, and 2e, respectively.Plant injury was determined as a percentage as compared to untreatedplants following a standard procedure wherein a visual assessment ofplant mortality and growth reduction is made by one skilled in the artspecially trained to make such assessments.

TABLE 2b % Control 1 DAT Form. TAROF FESAR PLAMA N479-2 0.0 0.0 0.0N479-3 0.0 0.0 0.0 N482-1 0.0 0.0 0.0 N482-4 0.0 0.0 0.0 N482-5 0.0 0.00.0 N485-1 0.0 0.0 0.0 N485-2 0.0 0.0 0.0 N485-3 0.0 0.0 0.0 N485-4 0.00.0 0.0 N485-5 0.0 0.0 0.0 N485-6 13.3 33.3 25.0 N485-7 13.3 50.0 20.0N485-8 28.3 73.3 21.7 M737 21.7 30.0 20.0

TABLE 2c % Control 3 DAT Form. TAROF FESAR PLAMA N479-2 23.3 53.3 60.0N479-3 36.7 55.0 50.0 N482-1 30.0 48.3 58.3 N482-4 23.3 53.3 56.7 N482-545.0 30.0 68.3 N485-1 43.3 45.0 36.7 N485-2 30.0 63.3 45.0 N485-3 40.060.0 30.0 N485-4 30.0 56.7 30.0 N485-5 33.0 70.0 40.0 N485-6 55.0 76.755.0 N485-7 63.3 80.0 46.7 N485-8 60.0 80.0 56.7 M737 53.3 70.0 25.0

TABLE 2d % Control 7 DAT Form. TAROF FES AR PLAMA N479-2 86.3 100.0 98.0N479-3 85.3 99.7 96.7 N482-1 85.3 100.0 96.7 N482-4 80.7 95.7 96.0N482-5 92.0 93.0 89.3 N485-1 88.3 97.3 94.0 N485-2 84.0 100.0 100.0N485-3 84.7 88.3 98.0 N485-4 88.0 100.0 98.7 N485-5 82.3 100.0 92.7N485-6 86.7 100.0 93.3 N485-7 82.7 100.0 96.0 N485-8 80.7 92.7 95.2 M73780.3 89.7 100.0

TABLE 2e % Control 15 DAT Form. TAROF FESAR PLAMA N479-2 94.7 96.7 100.0N479-3 94.7 100.0 100.0 N482-1 93.3 96.0 100.0 N482-4 90.7 98.3 96.7N482-5 94.7 100.0 100.0 N485-1 91.7 98.3 100.0 N485-2 100.0 100.0 100.0N485-3 90.7 100.0 100.0 N485-4 91.3 100.0 100.0 N485-5 97.3 96.7 100.0N485-6 94.7 100.0 100.0 N485-7 93.3 100.0 100.0 N485-8 91.3 96.7 100.0M737 88.0 100.0 100.0

The field efficacy of formulation 258 was evaluated. Formulation M258mixtures were applied at different rates to field of common dandelion(TAROF), perennial ryegrass (LOLPE), and broadleaf plantain (PLAMA)using a Mennen gel applicator, as described above. Injury ratings weretaken at 6, 13, 22, and 34 days after treatment. The data is provided inTables 2f-2i, respectively.

TABLE 2f Gel Rate Gly a.i. % Control 6 DAT Form g/weed Rate g/weed TAROFLOLPE PLAMA M258 0.7 0.007 46.7 95.3 66.7 M258 1.8 0.018 58.3 99.3 77.7M258 2.8 0.028 71.7 100.0 83.3

TABLE 2g Gel Rate Gly a.i. Rate % Control 13 DAT Form g/weed g/weedTAROF LOLPE PLAMA M258 0.7 0.007 60.0 100.0 76.0 M258 1.8 0.018 70.0100.0 91.3 M258 2.8 0.028 82.7 100.0 93.3

TABLE 2h Gel Rate Gly a.i. Rate % Control 22 DAT Form g/weed g/weedTAROF LOLPE PLAMA M258 0.7 0.007 72.7 100.0 90.0 M258 1.8 0.018 81.3100.0 100.0 M258 2.8 0.028 93.0 100.0 100.0

TABLE 2i Gel Rate Gly a.e. Rate % Control 34 DAT Form g/weed g/weedTAROF LOLPE PLAMA M258 0.7 0.007 85.0 100.0 90.0 M258 1.8 0.018 95.3100.0 100.0 M258 2.8 0.028 99.3 100.0 100.0

The field efficacy of additional gel mixtures prepared from Table II andTable III 26 mL of each gel formulations were applied by placing 26 mlof gel onto a sponge and wiping over the treated area to dandelion(TAROF), yellow nutsedge (CYPES), and broadleaf plantain (PLAMA). Injuryratings were taken at 1, 4, 7, and 13 days after treatment. The data isprovided in Tables 2j-2m, respectively.

TABLE 2j % Control 1 DAT Form TAROF CYPES PLAMA FESAW M261 28.3 10.022.5 66.7 M262 50.0 10.0 20.0 65.0 M257 1.7 1.7 1.7 0 M258 0.0 0.0 0.0 0CONTROL 0.0 0.0 0.0 0

TABLE 2k % Control 4 DAT Form TAROF CYPES PLAMA FESAW M261 66.7 48.3 5583.7 M262 68.3 30 33 85.3 M257 35.0 28.3 30 48.3 M258 45.0 27.5 28.331.7 CONTROL 0.0 0.0 0.0 0

TABLE 21 % Control 7 DAT Form TAROF CYPES PLAMA FESAW M261 85.0 63.365.0 94.0 M262 83.3 56.7 70.0 92.0 M257 81.7 58.3 73.3 87.3 M258 80.062.5 73.3 86.7 CONTROL 0.0 0.0 0.0 0

TABLE 2m % Control 13 DAT Form TAROF CYPES PLAMA FESAW M261 90.0 97.7100.0 100 M262 85.0 98.7 98.3 100 M257 90.0 97.0 95.0 100 M258 87.7 99.098.3 99.3 CONTROL 0.0 0.0 0.0 0

Gel formulations from Table III were sprayed with a trigger sprayer at aspray volume of approximately 1349 L/hectare to a typical lawn andgarden weed spectrum in a greenhouse setting. The weed spectrumconsisted of hairy crabgrass (DIGSA), tall fescue (FESAR), commonpurslane (POROL), white clover (TRFRE). Injury ratings were taken at 5and 14 DAT. Gel formulations were compared to commercial formulation,Roundup Super Concentrate (“RU SC”). The results are reported in Tables2n and 2o.

TABLE 2n % Control 5 DAT Form DIGSA FESAR POROL TRFRE RU SC (2.5 oz/gal)65.0 73.3 85.0 83.3 RU SC (0.09% ai) 40.0 38.3 40.0 55.5 RU SC (0.26%ai) 51.7 53.3 73.3 65.0 RU SC (0.5% ai) 63.3 71.7 94.3 68.3 RU SC (0.75%ai) 60.0 68.3 96.0 88.3 N893B 51.7 40.0 48.3 58.3 N893C 50.0 45.0 58.363.3 N894A 55.0 45.0 79.3 70.0 N894B 66.7 81.7 75.0 97.0

TABLE 2o % Control 14 DAT Form DIGSA FESAR POROL TRFRE RU SC (2.5oz/gal) 100.0 100.0 100.0 100.0 RU SC (0.09% ai) 65.0 90.0 83.3 71.7 RUSC (0.26% ai) 98.0 98.7 97.0 91.7 RU SC (0.5% ai) 100.0 100.0 100.0 98.0RU SC (0.75% ai) 100.0 100.0 100.0 99.7 N893B 70.0 90.3 90.3 77.7 N893C81.7 97.7 99.0 85.3 N894A 91.7 99.3 100.0 91.0 N894B 100.0 100.0 100.0100.0

The Data in Tables 2a-d demonstrate the gel formulations with pelargonicacid show equivalent fast developing symptoms to the liquid formulationat 1 DAT and equal control at 15 DAT. The data in tables 2 e-hdemonstrate that with as little as 0.7g of gel per weed 85% and abovecontrol of the weeds is obtained and with 1.8 and 2.8 g of gel per weed≥95% control is achieved. The data in table 2n and 2o demonstrate thatthe gel formulations provide equivalent control to a liquid formulationwhen applied at the same rate through a trigger sprayer.

When introducing elements of the present invention or the preferredembodiments(s) thereof, the articles “a”, “an”, “the” and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements. In view of the above, it will be seen that the several objectsof the invention are achieved and other advantageous results attained.

As various changes could be made in the above compositions and processeswithout departing from the scope of the invention, it is intended thatall matter contained in the above description and shown in theaccompanying drawing[s] shall be interpreted as illustrative and not ina limiting sense.

What is claimed is:
 1. An aqueous agrochemical gel compositioncomprising: (1) from 0.1 to 5 percent by weight on an acid equivalentbasis of a water-soluble agrochemical component comprising at least onewater-soluble agrochemical, (2) from 0.1 to 5 percent by weight of apolymeric gel forming agent component comprising at least one polymericgel forming agent, and (3) from 85 to 98 percent by weight water whereintan (delta) of the gel composition is less than 1 as measured byoscillation frequency sweep rheometric measurements between about 0.1and about 600 rad/sec at 0.2 Pa and 1 Pa as measured using a cone andplate viscometer method with a 60 mm 2° acrylic cone and plate at 20° C.and wherein the yield point of the gel composition is at least about 50dyne/cm².
 2. The gel composition of claim 1 wherein the yield point isat least about 75 dyne/cm².
 3. (canceled)
 4. (canceled)
 5. The gelcomposition of claim 1 wherein the polymeric gel forming componentcomprises at least one polymeric gel forming agent selected from thegroup consisting of polyacrylic acid, polyacrylamide, sodium acrylate,alkyl acrylate, hydroxypropyl cellulose, hydroxypropylmethyl cellulose,hydroxypropylethyl cellulose, hydroxypropylbutyl cellulose,hydroxypropylpentyl cellulose, hydroxyethyl cellulose, ethylcellulose,carboxymethyl cellulose, hydroxypropylmethyl cellulose phthalate,cellulose acetate acrylic acid ester, polyoxyethylene-polyoxypropylenecopolymer, poly(l-carboxyethylene), carboxypolymethylene prepared fromacrylic acid cross-linked with allyl ethers of (polyalkyl)sucrose orpentaerythritol, carboxyvinyl, polyvinyl pyrrolidone, polyvinyl alcohol,polyvinyl methyl ether, polyvinyl ether, polyvinyl sulfonate,polyethylene glycol, polysucrose, polyglucose, polylactose, polyethyleneoxide, poly(ethylene oxide)-co-poly(propylene oxide) block copolymer,poly(ethyloxazoline), gelatin, succinate, dextran, gaur-gum, tragacanth,xanthan gum, sodium alginate, sodium pectinate, acacia gum, Irish moss,karaya gum, guaiac gum, locust bean gum, casein, gelatin, collagen,albumin, cellulose, dextrin, pectin, starch, agar, mannan, and mixtures,copolymers and derivatives thereof.
 6. The gel composition of claim 5wherein the polymeric gel forming component comprises at least onepolymeric gel forming agent selected from the group consisting ofpolyacrylic acid, carboxymethyl cellulose and polysucrose.
 7. The gelcomposition of claim 1 wherein tan (delta) of the gel composition isfrom 0.05 to 0.9.
 8. The gel composition of claim 1 wherein thestationary viscosity of the gel composition is from about 500 to 150,000mPa second as measured according to a cone and plate viscometer methodusing a 60 mm 2° acrylic cone and plate at 20° C. with an oscillatingfrequency of 100 rad/s.
 9. The gel composition of claim 1 wherein thewater content is from 90 to 98 percent by weight.
 10. The gelcomposition of claim 1 wherein the water-soluble agrochemical content isfrom 0.5 to 5 percent by weight on an acid equivalent basis.
 11. The gelcomposition of claim 1 wherein the polymeric gel forming agent contentis from 1 to 5 percent by weight.
 12. The gel composition of claim 1wherein the gel composition is a pseudoplastic gel.
 13. The gelcomposition of claim 1 further comprising a preservative.
 14. The gelcomposition of claim 1 further comprising a surfactant componentcomprising at least one surfactant.
 15. The gel composition of claim 14wherein the surfactant component comprises at least one surfactantselected from the group consisting of alkoxylated tertiary etheramine,alkoxylated quaternary etheramine, alkoxylated tertiary amine oxide,alkoxylated tertiary amine, alkoxylated quaternary amine, alkoxylatedetheramine oxide, polyamine, sulfate derivative, sulfonate derivative,phosphate ester of alkoxylated alcohol, alkyl polysaccharide,alkoxylated alcohol, amidoalkylamine, and combinations thereof.
 16. Thegel composition of claim 1 wherein the water-soluble agrochemical isselected from the group consisting of herbicides, plant growthregulators, acaricides, insecticides, virucides, algicides,bactericides, fungicides, nematicides, herbicide safeners, plantactivators or synergists, and combinations thereof.
 17. The gelcomposition of claim 16 wherein the water-soluble agrochemical componentcomprises a water-soluble herbicide.
 18. The gel composition of claim 17wherein the water-soluble herbicide is selected from the groupconsisting of 2,4-D, 2,4-DB, aminopyralid, amitrole, asulam,azimsulfuron, beflubutamide, benazolin, bentazon, bispyribac-sodium,bromacil, carbetamide, carfentrazone-ethyl, chlorimuron-ethyl,chlorsulfuron, cinosulfuron, clopyralid, dicamba, dichlorprop, diclofop,diclopyr, difenzoquat, dimethenamid, dimethipin, diquat, DSMA,endothall, ethoxysulfuron, floramsulfuron, florasulam,flucarbazone-sodium, flumetsulam, fluroxypyr, fosamine, glyphosate,glufosinate, glufosinate-P, halosulfuron-methyl, hexazinone,imazamethabenz-m, imazamox, imazapic, imazapyr, imazaquin, imazethapyr,iodosulfuron, MCPA, MCPB, mecoprop, mecoprop-P, MSMA, naptalam,nicosulfuron, paraquat, water- soluble salts of pelargonic acid,penoxsulam, picloram, primisulfuron-methyl, propoxycarbazone-sodium,prosulfuron, pyrithiobac-sodium, sethoxydim, sulfentrazone,sulfosulfuron, tebuthiuron, tepraloxydim, thifensulfuron-methyl,tralkoxydim, triasulfuron, tribenuron-methyl, triclopyr,trifloxysulfuron and triflusulfuron-methyl, salts and esters thereof,and stereoisomers thereof.
 19. The gel composition of claim 18 whereinthe water-soluble herbicide is selected from the group consisting of asalt of glyphosate, an ester of glyphosate, and mixtures thereof. 20.The gel composition of claim 18 wherein the water-soluble herbicidecomprises a combination of two or more water-soluble co-herbicidesselected from the group consisting of glyphosate, 2,4-D, dicamba, MCPA,MCPB, triclopyr, imazamethabenz-m, imazamox, imazapic, imazapyr,imazaquin, imazethapyr, paraquat, diquat, and salts and esters thereof.21. The gel composition of claim 18 wherein the water-soluble herbicidecomprises a combination of two or more water-soluble co-herbicidesselected from the group consisting of glyphosate, 2,4-D, dicamba, MCPA,MCPB, triclopyr, imazamethabenz-m, imazamox, imazapic, imazapyr,imazaquin, imazethapyr, and salts and esters thereof.
 22. The gelcomposition of claim 18 further comprising at least one water-insolubleagrochemical dispersed therein selected from dithiopyr,pyraflufen-ethyl, acifluorfen, aclonifen, bifenox, chlomethoxyfen,chlornitrofen, etnipromid, fluorodifen, fluoroglycofen, fluoronitrofen,fomesafen, furyloxyfen, halosafen, lactofen, nitrofen, nitrofluorfen,oxyfluorfen and atrazine.
 23. (canceled)
 24. (canceled)
 25. The gelcomposition of claim 1 consisting essentially of at least onewater-soluble agrochemical, at least one polymeric gel forming agent, apreservative and water.
 26. The gel composition of any one of claims 1to 21 comprising from 0.5 to 1.5 percent by weight water-solubleagrochemical on an acid equivalent basis, from 2 to 4 percent by weightpolymeric gel forming agent and from 94 to 97.5 percent by weight water.27. A method for confined application of an agrochemical to plants, themethod comprising applying the agrochemical gel composition of claim 1to the plants.
 28. The method of claim 27 wherein the agrochemical gelcomposition is applied to the foliage of the plants with a hand-heldsprayer, a roller or a brush.
 29. The method of claim 27 wherein afoliage canopy is formed from the foliage of a plurality of the plantsand the agrochemical gel composition is applied to the foliage canopy.30. The method of claim 27 wherein the agrochemical gel composition isapplied to the plants by cut stump application, cut and swabapplication, stem scraping application or hack and squirt application.31. (canceled)
 32. (canceled)
 33. A method of confined application of awater-soluble herbicide to unwanted plants, the method comprisingapplying the agrochemical gel composition of claim 26 to the unwantedplants. Claims 34-88: (Canceled)